WorldWideScience

Sample records for trace no2 addition

  1. [Ammonia oxidation kinetics of ammonia oxidizer mixed culture under the conditions of O2 and trace NO2 mixed gasses].

    Science.gov (United States)

    Zhang, Dai-Jun; Zu, Bo; Ren, Hong-Yang; Zhang, Ping; Cong, Li-Ying; Yan, Qing

    2008-01-01

    The kinetics of the NO2-dependent ammonia oxidation was developed for ammonia oxidizer mixed culture when there was no molecular oxygen in the batch tests. The kinetics parameters were determined, where the half saturate coefficient of NO2 was 0.821 micromol x L(-1), inhibition coefficient of NO2 concentration was 1.721 micromol x L(-1), and the maximum ammonia oxidation rate were 0.144 mg x (mg x h)(-1). After adding the volume fraction of O2 was 2% to trace NO2, the ammonia oxidation rates increased obviously. The maximum ammonia oxidation rate, 0.198 mg x (mg x h)(-1) occurred under the condition of the mixed gasses containing the volume fraction of O2 was 2% and 50 x 10(-6) NO2. Under the condition of mixed gasses containing the volume fraction of O2 was 21% to trace NO2, the ammonia oxidation rates further increased greatly. The maximum ammonia oxidation rate, 0.477 mg x (mg x h)(-1) occurred when the volume fraction of O2 was 21% and 100 x 10(-6) NO2 in the mixed gas, which is 3 times higher than the general aerobic ammonia oxidation rate. The function for NO2 apparently to enhance ammonia oxidation was suggested. The kinetics model of ammonia oxidation under the conditions of O2 and trace NO2 mixed gasses was developed. The model was validated by the results of ammonia oxidation experiments under the conditions of the mixed gasses containing 2% O2 and trace NO2. The mechanism for NO2 to enhance ammonia oxidation under the conditions of O2 and trace NO2 mixed gasses was discussed.

  2. The influence of trace NO(2) on the kinetics of ammonia oxidation and the characteristics of nitrogen removal from wastewater.

    Science.gov (United States)

    Zhang, Daijun; Cai, Qing; Zu, Bo; Bai, Cui; Zhang, Ping

    2010-01-01

    Ammonia oxidizing bacteria-enriched sludge was obtained in a sequencing batch reactor with synthetic wastewater. Batch tests of ammonia oxidation were carried out with the sludge, in the presence of only trace NO(2) and in the presence of O(2) and trace NO(2), respectively. The Andrews model is used to describe NO(2)-dependent ammonia oxidation. The maximum ammonia oxidation rate of 139.11 mg N.(g sludge COD h)(-1), occurred in the presence of 21% O(2) and 100 ppm NO(2), which was 3 times higher than the aerobic ammonia oxidation rate without NO(2). The kinetic model of ammonia oxidation in the presence of O(2) and trace NO(2) is developed, and the function of NO(2) apparently enhancing ammonia oxidation is suggested. The maximal nitrogen removel of 34.19% occurred at the 21% O(2) and 100 ppm NO(2) in the mixed gases. Nitrogen removal principally depended on the denitrification activity and NO(2)-dependent ammonia oxidation activity of ammonia-oxidizing bacteria (AOB).

  3. A new method for the determination of NO2 traces using isotope dilution and mass spectrometry analysis

    International Nuclear Information System (INIS)

    Stevens, C.; Barat, F.; Nguyen Nghi, H.

    1975-01-01

    A new method for the determination of NO 2 traces, in the order of 1ppb (10 -9 ), in atmosphere and stratosphere is described. The method consists in an isotope dilution technique using 15 NO 2 , followed by the reduction of NO 2 to N 2 and a mass spectrometry analysis. A known amount of 15 NO 2 is added to the air samples. Then, NO 2 is separated from H 2 O, HNO 3 , CO 2 and N 2 O and transferred to a SiO 2 reactor by trapping at -196 deg C. In the reactor NO 2 is reduced to N 2 by reaction with electrolytic Cu heated at 580 deg C. The mass 29/mass 30 ratio corresponding to 15 N 14 N and 15 N 15 N is determined by mass spectrometry. The sensitivity of the method depends on the contamination introduced during the analysis of the sample (reagents, separation and measuring devices). The contamination is reproducible and in the order of 4.5+-0.5 10 -2 mm 3 N 2 [fr

  4. Operational O3M-SAF trace gas column products: GOME-2 ozone, NO2, BrO, SO2 and CH2O

    Science.gov (United States)

    Hao, Nan; Valks, Pieter; Loyola, Diego; de Smedt, Isabelle; van Roozendael, Michel; Theys, Nicolas; Rix, Meike; Koukouli, Mariliza; Balis, Dimitris; Lambert, Jean-Christopher; Pinardi, Gaia; Zimmer, Walter; Emmadi, Sunil

    This contribution focuses on the operational GOME-2 trace gas column products developed at the German Aerospace Centre, in the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF). We present an overview of the retrieval algorithms and exemplary results for ozone, NO2, BrO, SO2 and CH2O. These trace gas column products are retrieved with the GOME Data Processor (GDP) version 4.x algorithm and the UPAS system. Total ozone and NO2 are retrieved with the Differential Optical Absorption Spectroscopy (DOAS) method using the UV wavelength region around 330 nm and 435 nm respectively. An additional algorithm is applied to retrieve the tropospheric NO2 column for polluted con-ditions. The operational ozone and NO2 products are available for the users in near real time, i.e. within two hours after sensing. SO2 emissions from volcanic and anthropogenic sources can be measured by GOME-2 around 320 nm. For BrO and CH2O, optimal DOAS fitting windows have been determined for GOME-2 in the UV wavelength region. The GOME-2 ozone, total and tropospheric NO2, SO2, BrO, CH2O and cloud products from DLR have reached the operational EUMETSAT O3M-SAF status. All these products are routinely available to the users via EUMETCast, WMO/GTS and FTP in HDF5 and BUFR format. We present initial validation results for GOME-2 products using ground-based measurements, as well as comparisons with other satellite products, such as those from SCIAMACHY and OMI. The use of tropospheric NO2, SO2 and CH2O columns for air quality applications will be presented, including temporal evolution analyses for China. Furthermore, we will show examples of BrO under polar winter conditions.

  5. Automated addition of Chelex solution to tubes containing trace items

    DEFF Research Database (Denmark)

    Stangegaard, Michael; Hansen, Thomas Møller; Hansen, Anders Johannes

    2011-01-01

    Extraction of DNA from trace items for forensic genetic DNA typing using a manual Chelex based extraction protocol requires addition of Chelex solution to sample tubes containing trace items. Automated of addition of Chelex solution may be hampered by high viscosity of the solution and fast...... sedimentation rate of the Chelex beads. Here, we present a simple method that can be used on an Eppendorf epMotion liquid handler resolving these issues...

  6. Real time tracing of the kinetic process of NO3, N2O5 and NO2 with VOCs by long optical pathlength absorption spectroscopy

    Science.gov (United States)

    YI, Hongming; Wu, Tao; Lauraguais, Amélie; Semenov, Vladimir; Coeur-Tourneur, Cecile; Fertein, Eric; Gao, Xiaoming; Chen, Weidong

    2014-05-01

    Nitrate radical (NO3) and dinitrogen pentoxide (N2O5, formed through the reaction of NO3 with NO2 and is a large reservoir for NO3) are two key intermediates components in atmospheric nitrogen chemistry [1]. They affect directly the oxidation capacity of the atmosphere through reaction of NO3 with volatile organic compounds (VOCs). It's highly desirable to be able to perform in-situ, simultaneous and continuous monitoring of NO3 and N2O5 concentrations with high selectivity and fast response time. N2O5 is usually indirectly measured via optical measurement of NO3 after thermal dissociation of N2O5 to NO3 [2]. In this paper, we report on the recent development and application of optical method for in situ direct concentration measurements of NO3 and N2O5 in smog chamber. NO3 (as well as NO2) were simultaneously measured by open-path incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS) [3] based on a light emitted diode operating in the range of 635-675 nm, and N2O5 was monitored by means of open-path multi-pass absorption spectroscopy of an external cavity quantum cascade laser tunable from 1223 to 1263 cm-1 (~8 µm). Reaction of NO3 with VOCs (such as isoprene, formaldehyde, 2-methoxyphenal) as well as the equilibrium between NO3 and N2O5 during the VOCs oxidation by NO3 radical have been on-line traced with high temporal resolution: 1 s for NO3-NO2 and 25 s for N2O5. Experimental detail and preliminary results will be presented. Our present work demonstrated that modern photonic technologies can provide a direct and highly selective means for chemical kinetic study, for instance, bringing insight into reactive uptake for NO3 and N2O5 on the organic particles [4], which remain still unexplored with few exceptions. References [1] Paul S. Monks, "Gas-phase radical chemistry in the troposphere", Chem. Soc. Rev. 34 (2005) 376-395. [2] R.M. Varma, S.M. Ball, T. Brauers, H.-P. Dorn, U. Heitmann, R.L. Jones, U. Platt, D. Pöhler, A.A. Ruth, A

  7. Tracing of salicylic acid additive during precipitation of zirconium

    International Nuclear Information System (INIS)

    Bharati Misra, U.; Gopala Krishna, K.; Narasimha Murty, B.; Yadav, R.B.

    2011-01-01

    This paper presents the results of experimental study carried out to know whether the salicylic acid used as an additive during the precipitation of zirconium using ammonium hydroxide solution goes into the filtrate, remains in the hydrated zirconia or gets distributed between the both under the ambient conditions of precipitation. Keeping its simplicity and amenability to adopt on a routine basis, spectrophotometric method has been chosen for the purpose among the many methods available and the problems associated in determining salicylic acid in the presence of zirconium and the medial measures to circumvent the same have been brought out in detail. (author)

  8. Controlling the microstructure and properties of wire arc additive manufactured Ti–6Al–4V with trace boron additions

    International Nuclear Information System (INIS)

    Bermingham, M.J.; Kent, D.; Zhan, H.; StJohn, D.H.; Dargusch, M.S.

    2015-01-01

    This study demonstrates that trace boron addition to Ti–6Al–4V coupons produced by additive layer manufacturing is an effective way to eliminate the deleterious anisotropic microstructures often encountered with this manufacturing technique. Trace boron additions (up to 0.13 wt.%) to this alloy eliminate grain boundary-α and colony-α, and instead produce a homogeneous α-microstructure consisting of fine equiaxed α-grains in both as-deposited and heat treated coupons. Prior-β grains remain columnar with boron addition but become narrower due to the wider solidification range and growth restricting effect of the boron solute. Compared to unmodified Ti–6Al–4V alloy, Ti–6Al–4V modified with trace boron additions showed up to 40% improvement in plasticity with no loss in strength under uniaxial compression at room temperature. Boron additions were found to inhibit twinning transmission that causes sudden large load drops during deformation of the unmodified Ti–6Al–4V alloy in the heat treated condition

  9. Effects of nitrogen and water addition on trace element stoichiometry in five grassland species.

    Science.gov (United States)

    Cai, Jiangping; Weiner, Jacob; Wang, Ruzhen; Luo, Wentao; Zhang, Yongyong; Liu, Heyong; Xu, Zhuwen; Li, Hui; Zhang, Yuge; Jiang, Yong

    2017-07-01

    A 9-year manipulative experiment with nitrogen (N) and water addition, simulating increasing N deposition and changing precipitation regime, was conducted to investigate the bioavailability of trace elements, iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in soil, and their uptake by plants under the two environmental change factors in a semi-arid grassland of Inner Mongolia. We measured concentrations of trace elements in soil and in foliage of five common herbaceous species including 3 forbs and 2 grasses. In addition, bioaccumulation factors (BAF, the ratio of the chemical concentration in the organism and the chemical concentration in the growth substrate) and foliar Fe:Mn ratio in each plant was calculated. Our results showed that soil available Fe, Mn and Cu concentrations increased under N addition and were negatively correlated with both soil pH and cation exchange capacity. Water addition partly counteracted the positive effects of N addition on available trace element concentrations in the soil. Foliar Mn, Cu and Zn concentrations increased but Fe concentration decreased with N addition, resulting in foliar elemental imbalances among Fe and other selected trace elements. Water addition alleviated the effect of N addition. Forbs are more likely to suffer from Mn toxicity and Fe deficiency than grass species, indicating more sensitivity to changing elemental bioavailability in soil. Our results suggested that soil acidification due to N deposition may accelerate trace element cycling and lead to elemental imbalance in soil-plant systems of semi-arid grasslands and these impacts of N deposition on semi-arid grasslands were affected by water addition. These findings indicate an important role for soil trace elements in maintaining ecosystem functions associated with atmospheric N deposition and changing precipitation regimes in the future.

  10. Effects of nitrogen and water addition on trace element stoichiometry in five grassland species

    DEFF Research Database (Denmark)

    Cai, Jiangping; Weiner, Jacob; Wang, Ruzhen

    2017-01-01

    A 9-year manipulative experiment with nitrogen (N) and water addition, simulating increasing N deposition and changing precipitation regime, was conducted to investigate the bioavailability of trace elements, iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in soil, and their uptake by plants...... alleviated the effect of N addition. Forbs are more likely to suffer from Mn toxicity and Fe deficiency than grass species, indicating more sensitivity to changing elemental bioavailability in soil. Our results suggested that soil acidification due to N deposition may accelerate trace element cycling...... and lead to elemental imbalance in soil–plant systems of semi-arid grasslands and these impacts of N deposition on semi-arid grasslands were affected by water addition. These findings indicate an important role for soil trace elements in maintaining ecosystem functions associated with atmospheric N...

  11. Characterization of trace gases measured over Alberta oil sands mining operations: 76 speciated C2-C10 volatile organic compounds (VOCs), CO2, CH4, CO, NO, NO2, NOy, O3 and SO2

    Science.gov (United States)

    Simpson, I. J.; Blake, N. J.; Barletta, B.; Diskin, G. S.; Fuelberg, H. E.; Gorham, K.; Huey, L. G.; Meinardi, S.; Rowland, F. S.; Vay, S. A.; Weinheimer, A. J.; Yang, M.; Blake, D. R.

    2010-12-01

    Oil sands comprise 30% of the world's oil reserves and the crude oil reserves in Canada's oil sands deposits are second only to Saudi Arabia. The extraction and processing of oil sands is much more challenging than for light sweet crude oils because of the high viscosity of the bitumen contained within the oil sands and because the bitumen is mixed with sand and contains chemical impurities such as sulphur. Despite these challenges, the importance of oil sands is increasing in the energy market. To our best knowledge this is the first peer-reviewed study to characterize volatile organic compounds (VOCs) emitted from Alberta's oil sands mining sites. We present high-precision gas chromatography measurements of 76 speciated C2-C10 VOCs (alkanes, alkenes, alkynes, cycloalkanes, aromatics, monoterpenes, oxygenated hydrocarbons, halocarbons and sulphur compounds) in 17 boundary layer air samples collected over surface mining operations in northeast Alberta on 10 July 2008, using the NASA DC-8 airborne laboratory as a research platform. In addition to the VOCs, we present simultaneous measurements of CO2, CH4, CO, NO, NO2, NOy, O3 and SO2, which were measured in situ aboard the DC-8. Carbon dioxide, CH4, CO, NO, NO2, NOy, SO2 and 53 VOCs (e.g., non-methane hydrocarbons, halocarbons, sulphur species) showed clear statistical enhancements (1.1-397×) over the oil sands compared to local background values and, with the exception of CO, were greater over the oil sands than at any other time during the flight. Twenty halocarbons (e.g., CFCs, HFCs, halons, brominated species) either were not enhanced or were minimally enhanced (evaporative emissions from the oil sands and its products and/or from the diluent used to lower the viscosity of the extracted bitumen (i.e., C4-C9 alkanes, C5-C6 cycloalkanes, C6-C8 aromatics), together with CO; and (2) emissions associated with the mining effort, such as upgraders (i.e., CO2, CO, CH4, NO, NO2, NOy, SO2, C2-C4 alkanes, C2-C4 alkenes, C

  12. Influence of trace boron addition on the directional solidification characteristics of Ti-6Al-4V

    International Nuclear Information System (INIS)

    Srinivasan, Raghavan; Tamirisakandala, Sesh

    2010-01-01

    Trace boron addition to several titanium alloys results in a reduction in the as-cast grain size by an order of magnitude. TiB needles are observed along the prior beta grain boundaries and not the grain interior in these alloys, indicating that TiB needles are not sites for the heterogeneous nucleation of beta grains. This study seeks to understand the influence of the growth rate R on microstructure evolution and grain refinement in Ti-6Al-4V-0.1B alloy using directional solidification experiments and microstructural characterization.

  13. Dendrite-Free Li Deposition Using Trace-Amounts of Water as an Electrolyte Additive

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Jiangfeng; Xu, Wu; Bhattacharya, Priyanka; Engelhard, Mark H.; Henderson, Wesley A.; Zhang, Yaohui; Zhang, Jiguang

    2015-07-01

    Residual water presents in nonaqueous electrolytes has been widely regarded as a detrimental factor for lithium (Li) batteries. This is because water is highly reactive with the commonly used LiPF6 salt and leads to the formation of HF that corrodes battery materials. In this work, we demonstrate that a controlled trace-amount of water (25-100 ppm) can be an effective electrolyte additive for achieving dendrite-free Li metal deposition in LiPF6-based electrolytes and avoid its detrimental effect at the same time. Detailed analyses reveal that the trace amount of HF formed by the decomposition reaction of LiPF6 with water will be electrochemically reduced during initial Li deposition process to form a uniform and dense LiF-rich SEI layer on the surface of the substrate. This LiF-rich SEI layer leads to a uniform distribution of the electric field on the substrate surface and enables uniform and dendrite-free Li deposition. Meanwhile the detrimental effect of HF is diminished due to the consumption of HF in the LiF formation process. Microscopic analysis reveals that the as-deposited dendrite-free Li films exhibit a self-aligned and highly-compacted Li nanorods structure which is consistent with their charming blue color or known as structure color. These findings clearly demonstrate a novel approach to control the nucleation and grow process of Li metal films using well-controlled trace-amount of water. They also shine the light on the effect of water on other electrodeposition processes.

  14. Alkaline phosphatase activity in the subtropical ocean: insights from nutrient, dust and trace metal addition experiments

    Directory of Open Access Journals (Sweden)

    Claire eMahaffey

    2014-12-01

    Full Text Available Phosphorus is an essential nutrient for all life on earth. In the ocean, the most bioavailable form of phosphorus is inorganic phosphate, but in the extensive subtropical gyres, phosphate concentrations can be chronically low and limit primary productivity and nitrogen fixation. In these regions, organisms produce hydrolytic enzymes, such as alkaline phosphatase (AP, that enable them to utilize the more replete dissolved organic phosphorus (DOP pool to meet their cellular phosphorus demands. In this study, we synthesized data from 14 published studies and present our own findings from two research cruises (D326 and D361 in the eastern subtropical Atlantic to explore the relationship between AP activity (APA and nutrients, Saharan dust and trace metals. We found that below a threshold phosphate concentration of ~ 30 nM, APA increased with an inverse hyperbolic relationship with phosphate concentration. Meanwhile, DOP concentrations decreased with enhanced APA, indicating utilization of the DOP pool. We found APA rates were significantly higher in the subtropical Atlantic compared to the subtropical Pacific Ocean, even over the same low phosphate concentration range (0 to 50 nM. While the phosphate concentration may have a first order control on the APA rates, we speculate that other factors influence this basin scale contrast. Using bioassay experiments, we show that the addition of Saharan dust and zinc significantly increased the rate of APA. To our knowledge, our results are the first direct field-based evidence that APA is limited by zinc in the subtropical ocean. Further work is required to explore the relationship between trace metals such as iron and zinc, which are co-factors of phosphohydrolytic enzymes, specifically PhoX and PhoA, respectively, and APA in the ocean.

  15. Impact of trace element additives on anaerobic digestion of sewage sludge with in-situ carbon dioxide sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Linville, Jessica L.; Shen, Yanwen; Schoene, Robin P.; Nguyen, Maximilian; Urgun-Demirtas, Meltem; Snyder, Seth W.

    2016-09-01

    Anaerobic digestion (AD) of sludge at wastewater treatment plants can benefit from addition of essential trace metals such as iron, nickel and cobalt to increase biogas production for utilization in combined heat and power systems, fed into natural gas pipelines or as a vehicle fuel. This study evaluated the impact and benefits of Ni/Co and olivine addition to the digester at mesophilic temperatures. These additions supplement previously reported research in which iron-rich olivine (MgSiO4) was added to sequester CO2 in-situ during batch AD of sludge. Trace element addition has been shown to stimulate and stabilize biogas production and have a synergistic effect on the mineral carbonation process. AD with 5% w/v olivine and 1.5 mg/L Ni/Co addition had a 17.3% increase in methane volume, a 6% increase in initial exponential methane production rate and a 56% increase in methane yield (mL CH4/g CODdegraded) compared to the control due to synergistic trace element and olivine addition while maintaining 17.7% CO2 sequestration from olivine addition. Both first-order kinetic modeling and response surface methodology modeling confirmed the combined benefit of the trace elements and olivine addition. These results were significantly higher than previously reported results with olivine addition alone [1].

  16. Impact of the Manaus urban plume on trace gas mixing ratios near the surface in the Amazon Basin: Implications for the NO-NO2-O3 photostationary state and peroxy radical levels

    Science.gov (United States)

    Trebs, Ivonne; Mayol-Bracero, Olga L.; Pauliquevis, Theotonio; Kuhn, Uwe; Sander, Rolf; Ganzeveld, Laurens; Meixner, Franz X.; Kesselmeier, Jürgen; Artaxo, Paulo; Andreae, Meinrat O.

    2012-03-01

    We measured the mixing ratios of NO, NO2, O3, and volatile organic carbon as well as the aerosol light-scattering coefficient on a boat platform cruising on rivers downwind of the city of Manaus (Amazonas State, Brazil) in July 2001 (Large-Scale Biosphere-Atmosphere Experiment in Amazonia-Cooperative LBA Airborne Regional Experiment-2001). The dispersion and impact of the Manaus plume was investigated by a combined analysis of ground-based (boat platform) and airborne trace gas and aerosol measurements as well as by meteorological measurements complemented by dispersion calculations (Hybrid Single-Particle Lagrangian Integrated Trajectory model). For the cases with the least anthropogenic influence (including a location in a so far unexplored region ˜150 km west of Manaus on the Rio Manacapuru), the aerosol scattering coefficient, σs, was below 11 Mm-1, NOx mixing ratios remained below 0.6 ppb, daytime O3 mixing ratios were mostly below 20 ppb and maximal isoprene mixing ratios were about 3 ppb in the afternoon. The photostationary state (PSS) was not established for these cases, as indicated by values of the Leighton ratio, Φ, well above unity. Due to the influence of river breeze systems and other thermally driven mesoscale circulations, a change of the synoptic wind direction from east-northeast to south-southeast in the afternoon often caused a substantial increase of σs and trace gas mixing ratios (about threefold for σs, fivefold for NOx, and twofold for O3), which was associated with the arrival of the Manaus pollution plume at the boat location. The ratio Φ reached unity within its uncertainty range at NOx mixing ratios of about 3 ppb, indicating "steady-state" conditions in cases when radiation variations, dry deposition, emissions, and reactions mostly involving peroxy radicals (XO2) played a minor role. The median midday/afternoon XO2 mixing ratios estimated using the PSS method range from 90 to 120 parts per trillion (ppt) for the remote cases (

  17. IDEA papers no 2

    International Nuclear Information System (INIS)

    Cassou, O.

    2002-09-01

    The Information network on the Economic Development in Aquitaine (IDEA) aims to collect and spread the environmental information concerning the Aquitaine, in order to implement an observatory of the regional environment and of the sustainable development. The IDEA paper no. 2 is devoted to the IDEA missions and their cooperation with ''Alliance pour la qualite et la performance''. This association groups actors for the development and the promotion of the quality. (A.L.B.)

  18. Modified batch anaerobic digestion assay for testing efficiencies of trace metal additives to enhance methane production of energy crops.

    Science.gov (United States)

    Brulé, Mathieu; Bolduan, Rainer; Seidelt, Stephan; Schlagermann, Pascal; Bott, Armin

    2013-01-01

    Batch biochemical methane potential (BMP) assays to evaluate the methane yield of biogas substrates such as energy crops are usually carried out with undiluted inoculum. A BMP assay was performed on two energy crops (green cuttings and grass silage). Anaerobic digestion was performed both with and without supplementation of three commercial additives containing trace metals in liquid, solid or adsorbed form (on clay particles). In order to reveal positive effects of trace metal supplementation on the methane yield, besides undiluted inoculum, 3-fold and 10-fold dilutions of the inoculum were applied for substrate digestion. Diluted inoculum variants were supplemented with both mineral nutrients and pH-buffering substances to prevent a collapse of the digestion process. As expected, commercial additives had no effect on the digestion process performed with undiluted inoculum, while significant increases of methane production through trace element supplementation could be observed on the diluted variants. The effect of inoculum dilution may be twofold: (1) decrease in trace metal supplementation from the inoculum and (2) reduction in the initial number of bacterial cells. Bacteria require higher growth rates for substrate degradation and hence have higher trace element consumption. According to common knowledge of the biogas process, periods with volatile fatty acids accumulation and decreased pH may have occurred in the course ofanaerobic digestion. These effects may have led to inhibition, not only ofmethanogenes and acetogenes involved in the final phases of methane production, but also offibre-degrading bacterial strains involved in polymer hydrolysis. Further research is required to confirm this hypothesis.

  19. Marginalia no. 2

    OpenAIRE

    Library, Merrill-Cazier

    1997-01-01

    Volume 1, Number 2 (Issue no. 2): Winter issue 1997 INTO A BRAVE NEW WORLD?-Guest commentator, Prof. Larry Cannon on the loss of the card catalogue INTERNET WIZARDRY- Kevin Brewer describes interesting Web sites and how to access them. BETTER THAN CASH-Giving Through capital gains profits “FRIENDSHIP FOR LIBRARIES”-What Friends offer & what it members get back JOIN FRIENDS COUPON & REPLY ENVELOPE EUPHORIA OF READING-Fungus on old paper & ‘enlightening’ drug-like euphoria ...

  20. Ractopamine, a Livestock Feed Additive, Is a Full Agonist at Trace Amine–Associated Receptor 1

    Science.gov (United States)

    Grandy, David K.; Janowsky, Aaron

    2014-01-01

    Ractopamine (RAC) is fed to an estimated 80% of all beef, swine, and turkey raised in the United States. It promotes muscle mass development, limits fat deposition, and reduces feed consumption. However, it has several undesirable behavioral side effects in livestock, especially pigs, including restlessness, agitation, excessive oral-facial movements, and aggressive behavior. Numerous in vitro and in vivo studies suggest RAC’s physiological actions begin with its stimulation of β1- and β2-adrenergic receptor–mediated signaling in skeletal muscle and adipose tissue; however, the molecular pharmacology of RAC’s psychoactive effects is poorly understood. Using human cystic fibrosis transmembrane conductance regulator (hCFTR) chloride channels as a sensor for intracellular cAMP, we found that RAC and p-tyramine (TYR) produced concentration-dependent increases in chloride conductance in oocytes coexpressing hCFTR and mouse trace amine–associated receptor 1 (mTAAR1), which was completely reversed by the trace amine–associated receptor 1 (TAAR1)–selective antagonist EPPTB [N-(3-ethoxyphenyl)-4-pyrrolidin-1-yl-3-trifluoromethylbenzamide]. Oocytes coexpressing hCFTR and the human β2-adrenergic receptor showed no response to RAC or TYR. These studies demonstrate that, contrary to expectations, RAC is not an agonist of the human β2-adrenergic receptor but rather a full agonist for mTAAR1. Since TAAR1-mediated signaling can influence cardiovascular tone and behavior in several animal models, our finding that RAC is a full mTAAR1 agonist supports the idea that this novel mechanism of action influences the physiology and behavior of pigs and other species. These findings should stimulate future studies to characterize the pharmacological, physiological, and behavioral actions of RAC in humans and other species exposed to this drug. PMID:24799633

  1. Ractopamine, a livestock feed additive, is a full agonist at trace amine-associated receptor 1.

    Science.gov (United States)

    Liu, Xuehong; Grandy, David K; Janowsky, Aaron

    2014-07-01

    Ractopamine (RAC) is fed to an estimated 80% of all beef, swine, and turkey raised in the United States. It promotes muscle mass development, limits fat deposition, and reduces feed consumption. However, it has several undesirable behavioral side effects in livestock, especially pigs, including restlessness, agitation, excessive oral-facial movements, and aggressive behavior. Numerous in vitro and in vivo studies suggest RAC's physiological actions begin with its stimulation of β1- and β2-adrenergic receptor-mediated signaling in skeletal muscle and adipose tissue; however, the molecular pharmacology of RAC's psychoactive effects is poorly understood. Using human cystic fibrosis transmembrane conductance regulator (hCFTR) chloride channels as a sensor for intracellular cAMP, we found that RAC and p-tyramine (TYR) produced concentration-dependent increases in chloride conductance in oocytes coexpressing hCFTR and mouse trace amine-associated receptor 1 (mTAAR1), which was completely reversed by the trace amine-associated receptor 1 (TAAR1)-selective antagonist EPPTB [N-(3-ethoxyphenyl)-4-pyrrolidin-1-yl-3-trifluoromethylbenzamide]. Oocytes coexpressing hCFTR and the human β2-adrenergic receptor showed no response to RAC or TYR. These studies demonstrate that, contrary to expectations, RAC is not an agonist of the human β2-adrenergic receptor but rather a full agonist for mTAAR1. Since TAAR1-mediated signaling can influence cardiovascular tone and behavior in several animal models, our finding that RAC is a full mTAAR1 agonist supports the idea that this novel mechanism of action influences the physiology and behavior of pigs and other species. These findings should stimulate future studies to characterize the pharmacological, physiological, and behavioral actions of RAC in humans and other species exposed to this drug. U.S. Government work not protected by U.S. copyright.

  2. Field investigations of nitrogen dioxide (NO2 exchange between plants and the atmosphere

    Directory of Open Access Journals (Sweden)

    J. Kesselmeier

    2013-01-01

    Full Text Available The nitrogen dioxide (NO2 exchange between the atmosphere and needles of Picea abies L. (Norway Spruce was studied under uncontrolled field conditions using a dynamic chamber system. This system allows measurements of the flux density of the reactive NO-NO2-O3 triad and additionally of the non-reactive trace gases CO2 and H2O. For the NO2 detection a highly NO2 specific blue light converter was used, which was coupled to chemiluminescence detection of the photolysis product NO. This NO2 converter excludes known interferences with other nitrogen compounds, which occur by using more unspecific NO2 converters. Photo-chemical reactions of NO, NO2, and O3 inside the dynamic chamber were considered for the determination of NO2 flux densities, NO2 deposition velocities, as well as NO2 compensation point concentrations. The calculations are based on a bi-variate weighted linear regression analysis (y- and x-errors considered. The NO2 deposition velocities for spruce, based on projected needle area, ranged between 0.07 and 0.42 mm s−1. The calculated NO2 compensation point concentrations ranged from 2.4 ± 9.63 to 29.0 ± 16.30 nmol m−3 (0.05–0.65 ppb but the compensation point concentrations were all not significant in terms of compensation point concentration is unequal to zero. These data challenge the existence of a NO2 compensation point concentration for spruce. Our study resulted in lower values of NO2 gas exchange flux densities, NO2 deposition velocities and NO2 compensation point concentrations in comparison to most previous studies. It is essential to use a more specific NO2 analyzer than used in previous studies and to consider photo-chemical reactions between NO, NO2, and O3 inside the chamber.

  3. Impact of the Manaus urban plume on trace gas mixing ratios near the surface in the Amazon Basin: Implications for the NO-NO2-O-3 photostationary state and peroxy radical levels

    NARCIS (Netherlands)

    Trebs, I.; Mayol-Bracero, O.L.; Pauliquevis, T.; Kuhn, U.; Sander, R.; Ganzeveld, L.N.; Meixner, F.X.; Kesselmeier, J.; Artaxo, P.; Andreae, M.O.

    2012-01-01

    We measured the mixing ratios of NO, NO2, O-3, and volatile organic carbon as well as the aerosol light-scattering coefficient on a boat platform cruising on rivers downwind of the city of Manaus (Amazonas State, Brazil) in July 2001 (Large-Scale Biosphere-Atmosphere Experiment in

  4. Reservoir-Scale Biological Community Response to Trace Element Additions in a Northern Montana Oil Field

    Science.gov (United States)

    Connors, D. E.; Bradfish, J.; DeBruyn, R. P.; Zemetra, J.; Mitchell, H.

    2017-12-01

    In subsurface oil bearing formations, microbial growth and metabolism is restricted due to a lack of elements other than carbon, hydrogen, and oxygen required for cell structure and as cofactors. A chemical treatment that adds these elements back into the formation was deployed into an oil reservoir in Northern Montana, with the intent of increasing biogenic methane generation. Samples of water from producing wells in the reservoir were collected anaerobically, and analyzed for geochemical content, and cells from the water were collected and analyzed via 16S rRNA gene DNA sequencing to determine the makeup of the microbial community over the course of twelve months of treatment, and for two years after. Prior to chemical treatment, this reservoir was depleted in elements required for enzyme co-factors in the methanogenesis metabolic pathway (Co, Mo, Ni, W, Zn) as well as nitrogen and phosphorus. Most the microbial community was composed of chemoheterotrophic bacteria associated with the biodegradation of large carbon molecules, with a small community of acetoclastic methanogens. During and after additions of the depleted elements, the metabolism of the community in the reservoir shifted towards chemoautotrophs and hydrogenotrophic methanogens, and the cell density increased. After treatment was ended, cell counts stabilized at a new equilibrium concentration, and the autotrophic metabolism was maintained. The pre-treatment community was dependent on energy input from solubilized oil molecules, whereas the post-treatment community more effectively utilized dissolved organics and carbon dioxide as carbon sources for fixation and respiration. This study demonstrates the capability of microbial communities to rapidly reorganize in the environment when provided with an influx of the elements required for growth and metabolism.

  5. Hybrid calcium phosphate coatings with the addition of trace elements and polyaspartic acid by a low-thermal process

    Energy Technology Data Exchange (ETDEWEB)

    Xu Sanzhong; Lin Xiangjin [The First Affiliated Hospital, College of Medicine of Zhejiang University, Hangzhou 310003 (China); Yang Xianyan; Chen Xiaoyi; Gao Changyou; Gou Zhongru [Zhejiang-California International NanoSystems Institute, Zhejiang University, Hangzhou 310029 (China); Zhang Lei; Yang Guojing, E-mail: zhrgou@zju.edu.cn [Rui' an People' s Hospital and the 3rd Hospital Affiliated to Wenzhou Medical College, Rui' an 325200 (China)

    2011-06-15

    Research in the field of orthopedic implantology is currently focused on developing methodologies to potentiate osseointegration and to expedite the reestablishment of full functionality. We have developed a simple biomimetic approach for preparing trace elements-codoped calcium phosphate (teCaP) coatings on a titanium substrate. The reaction proceeded via low-thermal incubation in trace elements (TEs)-added simulated body fluid (teSBF) at 90 and 120 deg. C. The x-ray photoelectron spectroscopy, x-ray diffraction and energy-dispersive x-ray analyses demonstrated that the teCaP coating was the composite of hydroxyapatite and whitlockite, simultaneously doped with magnesium, strontium, zinc and silicon. The addition of polyaspartic acid and TEs into SBF significantly densified the coating. The incubation temperature is another important factor controlling the coating precipitation rate and bonding strength. An incubation temperature of 120 deg. C could accelerate the coating precipitation and improve the interface bonding strength. The in vitro cell culture investigation indicated that the teCaP coating supported the adhesion and spreading of ovariectomized rat mesenchymal stem cells (rMSCs) and particularly, promoted rMSCs proliferation compared to the CaP coating prepared in SBF. Collectively, from such a biomimetic route there potentially arises a general procedure to prepare a wide range of bioactive teCaP coatings of different composition for osteoporotic osteogenic cells activation response.

  6. Chapter No.2. Legislation

    International Nuclear Information System (INIS)

    2002-01-01

    UJD as the central body of state administration prepares legislation within their competency and sets also binding criteria in the field of nuclear safety. Based on provisions of the 'Atomic Act' the preparation of rest regulations has continued. Following drafts of 5 were prepared regulations in 2001 and then they were sent for comments to various ministries by UJD: (a) Regulation on safety requirements for design of nuclear installations; (b) Regulation on safety requirements for commissioning and operation of nuclear installations; (c) Regulation on safety documentation; (d) Regulation on periodic safety assessment; (e) Regulation on safety requirements for siting of nuclear installations. Two following UJD safety guides were published in 2001 as the part of edition 'Safety of Nuclear Installations': (a) BNS I. 11.2/1999 'Requirements for performance of safety analyses for ATWS' (b) BNS II.3.1/2000 'Evaluation of acceptability of faults detected during the operation inspection of nuclear installation selected equipment'. As UJD is responsible for performance of such reviews according to law No. 264/1999 Coll. on conformance assessment of products about 10 drafts of technical standards were reviewed. UJD provided documentation to the Slovak Republic position document related to Chapter 14 - Energy which was submitted to the European Union (EU). The set of recommendations related to nuclear safety was elaborated by the special working group on atomic question which was established by the EU Council. Their implementation is required as a prerequisite to close negotiations on Chapter 14 - Energy. The schedule of necessary safety related measures was agreed in co-operation with the SE a.s. and the Ministry of Economy and submitted as additional information for negotiations to the EC. The negotiations on Chapter 14 - Energy were successfully closed in October 2001. The activities in the area of Chapter 22 - Environment were concentrated on submission of necessary data

  7. Concentrations and uncertainties of stratospheric trace species inferred from limb infrared monitor of the stratosphere data. I - Methodology and application to OH and HO2. II - Monthly averaged OH, HO2, H2O2, and HO2NO2

    Science.gov (United States)

    Kaye, J. A.; Jackman, C. H.

    1986-01-01

    Difficulties arise in connection with the verification of multidimensional chemical models of the stratosphere. The present study shows that LIMS data, together with a photochemical equilibrium model, may be used to infer concentrations of a variety of zonally averaged trace Ox, OHx, and NOx species over much of the stratosphere. In the lower stratosphere, where the photochemical equilibrium assumption for HOx species breaks down, inferred concentrations should still be accurate to about a factor of 2 for OH and 2.5 for HO2. The algebraic nature of the considered model makes it possible to see easily to the first order the effect of variation of any model input parameter or its uncertainty on the inferred concontration of the HOx species and their uncertainties.

  8. Photodissociation constant of NO2

    International Nuclear Information System (INIS)

    Nootebos, M.A.; Bange, P.

    1992-01-01

    The velocity of the dissociation of NO 2 into ozone and NO mainly depends on the ultraviolet sunlight quantity, and with that the cloudiness. A correct value for this reaction constant is important for the accurate modelling of O 3 - and NO 2 -concentrations in plumes of electric power plants, in particular in the case of determination of the amount of photochemical summer smog. An advanced signal processing method (deconvolution, correlation) was applied on the measurements. The measurements were carried out from aeroplanes

  9. Volume 7 No. 2 2007

    African Journals Online (AJOL)

    ROP4

    communities in Butere, and three of the eight communities, in Khwisero. The ... 3. Volume 7 No. 2 2007. INTRODUCTION. Micronutrient malnutrition is recognized as a serious threat to the health and productivity of people. Deficiencies in three major ... They also have uncontested advantage of allowing for the natural.

  10. Airborne measurements of spatial NO2 distributions during AROMAT

    Science.gov (United States)

    Meier, Andreas Carlos; Seyler, André; Schönhardt, Anja; Richter, Andreas; Ruhtz, Thomas; Lindemann, Carsten; Burrows, John P.

    2015-04-01

    Nitrogen oxides, NOx (NOx = NO + NO2) play a key role in tropospheric chemistry. In addition to their directly harmful effects on the respiratory system of living organisms, they influence the levels of tropospheric ozone and contribute to acid rain and eutrophication of ecosystems. As they are produced in combustion processes, they can serve as an indicator for anthropogenic air pollution. In September 2014 several European research groups conducted the ESA funded Airborne ROmanian Measurements of Aerosols and Trace gases (AROMAT) campaign to test and intercompare newly developed airborne observation sytsems dedicated to air quality satellite validation studies. The IUP Bremen contributed to this campaign with its Airborne imaging DOAS instrument for Measurements of Atmospheric Pollution (AirMAP) on board a Cessna 207 turbo, operated by the FU Berlin. AirMAP allows the retrieval of integrated NO2 column densities in a stripe below the aircraft at a fine spatial resolution of up to 30 x 80 m2, at a typical flight altitude. Measurements have been performed over the city of Bucharest, creating for the first time high spatial resolution maps of Bucharest's NO2 distribution in a time window of approx. 2 hours. The observations were synchronised with ground-based car MAX-DOAS measurements for comparison. In addition, measurements were taken over the city of Berlin, Germany and at the Rovinari power plant, Romania. In this work the results of the research flights will be presented and conclusions will be drawn on the quality of the measurements, their applicability for satellite data validation and possible improvements for future measurements.

  11. Additional considerations for trace element analysis of environmental matrices using inductively coupled plasma atomic emission spectrometry with ultrasonic nebulization

    Energy Technology Data Exchange (ETDEWEB)

    Hoenig, M.; Baeten, H. [Cerva, Tervuren (Belgium); Docekalova, H. [Brno Univ. Technical, Faculty of Chemistry (Czech Republic)

    2000-06-01

    This work compares efficiencies of pneumatic and ultrasonic nebulizers and discusses drawbacks observed in trace element analyses of environmental matrices using ICP-AES with ultrasonic nebulization. The interference observed is mainly due to variable calcium content in samples; in most cases the excessive plasma loading by Ca'is responsible for signal suppression of analyte elements. Such matrix effect may be managed to a certain extent using a classical internal standardisation that is discussed in details. Under well defined conditions, the ICP-AES-USN analysis of most trace elements leads to accurate results for matrices usually studied. However, due to chemical reactions occurring in the condensation stage of the ultrasonic nebulizer and subsequent analyte losses to the waste, the ICP-AES-USN analysis of copper and particularly of boron has to be avoided because it leads unavoidably to erroneous results. This drawback cannot be resolved by usual means of correction but may be overcome by using conventional pneumatic nebulizers. (authors)

  12. Zeeman effect in NO2

    International Nuclear Information System (INIS)

    Bonilla, I.R.

    1984-01-01

    The gyromagnetic factors of the molecule NO 2 , in the Zeeman Effect, is measured under high resolution spectroscopy. The values 0.103 + - 0.007; 0.060 + - 0.005 and 0.045 + - 0.004 are found for the components α, β and γ respectively, by applying a magnetic field of 40 Gauss. For fields greater than 1 kilogauss decoupling of the electronic spin to the rotational angular momentum of the molecule is observed. Under this condition the value 1.86 + - 0.25 is obtained for the gyromagnetic factor. (Author) [pt

  13. How well does cloud correction of satellite observations of tropospheric NO2 work?

    Science.gov (United States)

    Munassar, Saqr; Richter, Andreas; Hilboll, Andreas; Behrens, Lisa K.; Burrows, John P.

    2017-04-01

    Satellite observations of tropospheric trace gases are limited by the presence of clouds which block part of the troposphere from the satellite view (shielding effect). They also enhance the sensitivity of satellite observations to absorbers located above clouds (albedo effect). In order to correct for these effects, most satellite data products use cloud correction schemes which apply cloud fraction and cloud height retrieved from measurements of columns of O2 or the O2-O2 dimer in combination with radiative transfer calculations. If the vertical profile of the trace gas of interest is known, such correction approaches can in theory remove most of the cloud dependence from the retrieved tropospheric columns. In practice however, neither the cloud parameters nor the vertical distribution of reactive gases such as NO2 are well known, and it is therefore useful to investigate how well the current approaches used for cloud correction work on real data. In this study, several versions of the FRESCO+ and O2-O2 cloud retrievals are applied to GOME2a and OMI data. The retrieved cloud parameters as well as the resulting tropospheric NO2 columns are compared between algorithm versions and between instruments for a number of selected regions in polluted, background and biomass burning regions. In addition, different sources are used for the a priori NO2 profiles used in the retrieval. The results show that differences in cloud parameters between algorithm versions and instruments can be quite large, but effects on tropospheric NO2 columns are limited. Comparison of model predicted and observed cloud fraction dependency of tropospheric NO2 slant columns disagrees in many regions in particular over China, where the largest NO2 columns are not observed at smallest cloud fractions as expected. As a result, tropospheric NO2 vertical columns have a significant cloud fraction dependency, indicating that improvements are needed to further reduce cloud related uncertainties.

  14. Biochemical methane potential from sewage sludge: Effect of an aerobic pretreatment and fly ash addition as source of trace elements.

    Science.gov (United States)

    Huiliñir, César; Pinto-Villegas, Paula; Castillo, Alejandra; Montalvo, Silvio; Guerrero, Lorna

    2017-06-01

    The effect of aerobic pretreatment and fly ash addition on the production of methane from mixed sludge is studied. Three assays with pretreated and not pretreated mixed sludge in the presence of fly ash (concentrations of 0, 10, 25, 50, 250 and 500mg/L) were run at mesophilic condition. It was found that the combined use of aerobic pretreatment and fly ash addition increases methane production up to 70% when the fly ash concentrations were lower than 50mg/L, while concentrations higher than 250mg/L cause up to 11% decrease of methane production. For the anaerobic treatment of mixed sludge without pretreatment, the fly ash improved methane generation at all the concentrations studied, with a maximum of 56%. The removal of volatile solids does not show an improvement compared to the separate use of an aerobic pre-treatment and fly ash addition. Therefore, the combined use of the aerobic pre-treatment and fly ash addition improves only the production of methane. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Impact of NO2 Profile Shape in OMI Tropospheric NO2 Retrievals

    Science.gov (United States)

    Lamsal, Lok; Krotkov, Nickolay A.; Pickering, K.; Schwartz, W. H.; Celarier, E. A.; Bucsela, E. J.; Gleason, J. F.; Philip, S.; Nowlan, C.; Martin, R. V.; hide

    2013-01-01

    Nitrogen oxides (NOx NO + NO2) are key actors in air quality and climate change. Tropospheric NO2 columns from the nadir-viewing satellite sensors have been widely used to understand sources and chemistry of NOx. We have implemented several improvements to the operational algorithm developed at NASA GSFC and retrieved tropospheric NO2 columns. We present tropospheric NO2 validation studies of the new OMI Standard Product version 2.1 using ground-based and in-situ aircraft measurements. We show how vertical profile of scattering weight and a-priori NO2 profile shapes, which are taken from chemistry-transport models, affect air mass factor (AMF) and therefore tropospheric NO2 retrievals. Users can take advantage of scattering weights information that is made available in the operational NO2 product. Improved tropospheric NO2 data retrieved using thoroughly evaluated high spatial resolution NO2 profiles are helpful to test models.

  16. Volume 8 No. 2 2008 June 2008

    African Journals Online (AJOL)

    HomeComp

    Turkana doum palm nut whereas traces of palmitoleic acid are present in the palm kernel and coconut oil extracts. All the three fruits contain substantial amounts of oleic acid. However, the kernel of the Turkana doum palm nut has a higher oleic acid content than the kernel oils of both, the palm and coconut (21.9, 11.4 and ...

  17. The AOTF-Based NO2 Camera

    Science.gov (United States)

    Dekemper, E.; Fussen, D.; Vanhellemont, F.; Vanhamel, J.; Pieroux, D.; Berkenbosch, S.

    2017-12-01

    In an urban environment, nitrogen dioxide is emitted by a multitude of static and moving point sources (cars, industry, power plants, heating systems,…). Air quality models generally rely on a limited number of monitoring stations which do not capture the whole pattern, neither allow for full validation. So far, there has been a lack of instrument capable of measuring NO2 fields with the necessary spatio-temporal resolution above major point sources (power plants), or more extended ones (cities). We have developed a new type of passive remote sensing instrument aiming at the measurement of 2-D distributions of NO2 slant column densities (SCDs) with a high spatial (meters) and temporal (minutes) resolution. The measurement principle has some similarities with the popular filter-based SO2 camera (used in volcanic and industrial sulfur emissions monitoring) as it relies on spectral images taken at wavelengths where the molecule absorption cross section is different. But contrary to the SO2 camera, the spectral selection is performed by an acousto-optical tunable filter (AOTF) capable of resolving the target molecule's spectral features. A first prototype was successfully tested with the plume of a coal-firing power plant in Romania, revealing the dynamics of the formation of NO2 in the early plume. A lighter version of the NO2 camera is now being tested on other targets, such as oil refineries and urban air masses.

  18. Volume 8 No. 2 2008 June 2008

    African Journals Online (AJOL)

    HomeComp

    but eaten raw as fresh fruits. Coconuts contain ... beverage and food industries and this has stimulated interest in their formation and stability. Foams are .... Volume 8 No. 2 2008. June 2008. 176. Fig 1. Effect of PH on nitrogen solubility of fullfat Coconut protein concentrate (FFC-PC) at different salt concentrations. (%). 0. 10.

  19. JUST Vol. 28 No. 2, August, 2007

    African Journals Online (AJOL)

    level of the soil may account for the lack of sig- nificant soil improvement even in plots mulched and/or treated with fertilizer. This confirms re- ports on a Leucaena alley cropping trials in Zam-. 66 Journal of Science and Technology, Volume 27 no. 2, August, 2007. Evaluation of the effect of hedgerow intercropping .

  20. JUST Vol. 28 No. 2 Aug 2008

    African Journals Online (AJOL)

    ben

    2008-08-02

    Aug 2, 2008 ... 1848 when it became possible to think of the world as one unified economy. Keywords: world history, world society, capital, working class. Journal of Science and Technology, Vol. 28, No. 2, August, 2008 ..... These were the communication media for integrating the world into a single economy and hence a ...

  1. JUST Vol. 28 No. 2, August, 2007

    African Journals Online (AJOL)

    Journal of Science and Technology, Volume 27 no. 2, August, 2007. Nitrogen use efficiency of poultry manure. Boateng et. al. PDF Created with deskPDF PDF .... Experimental design. The trial consisted of eight treatments replicated five times in a randomized complete block de- sign. Each plot measured 5.0 m x 6.0 m ...

  2. Volume 8 No. 2 2008 June 2008

    African Journals Online (AJOL)

    HomeComp

    Volume 8 No. 2 2008. June 2008. 221. INTRODUCTION. Poverty followed by malnutrition and starvation is the growing and common phenomena mostly in .... The great majority of the farmers in Eritrea operate agriculture on small scale. ... Most small farmers operate on an independent basis, either as independent land.

  3. JUST Vol. 28 No. 2, August, 2007

    African Journals Online (AJOL)

    132 Journal of Science and Technology, Volume 27 no. 2, August, 2007 .... To make an im- pact on the market price there should be waiver ... TOURISM. Tourism will be greatly improved if tourists are able to locate their positions through the use of navigation systems, or if a control centre can plan and monitor the trips of ...

  4. JUST Vol. 28 No. 2 Aug 2008

    African Journals Online (AJOL)

    ben

    2008-08-02

    Aug 2, 2008 ... Machine learn. 5: 313 – 321. Schapire, R. and Singer, Y. (1999). Improved boosting algorithm using confidence rated prediction. Machine learn. 37: 297 – 336. Journal of Science and Technology, Vol. 28, No. 2, August, 2008 73. A meshsize boosting algorithm in kernel density estimation. Ishiekwene et al.

  5. JUST Vol. 28 No. 2 Aug 2008

    African Journals Online (AJOL)

    ben

    2008-08-02

    Aug 2, 2008 ... appearances, but they do not know the right out- fits that are suitable for their body proportions and figure types. Some of the common com- plaints are “my legs are too skinny”; “I am thin and flat chested”; “my shoulders are too broad”;. Journal of Science and Technology, Vol. 28, No. 2, August, 2008 133.

  6. Requirement-specific use of trace element biogas additives under consideration of the bioavailability; Bedarfsgerechter Einsatz von Spurenelement-Biogasadditiven unter Beruecksichtigung der Bioverfuegbarkeit

    Energy Technology Data Exchange (ETDEWEB)

    Feher, Adam; Fritz, Thomas; Loewen, Achim; Nelles, Michael [HAWK Hochschule fuer Angewandte Wissenschaft und Kunst Hildesheim/Holzminden/Goettingen, Goettingen (Germany). Fachgebiet Nachhaltige Energie- und Umwelttechnik (NEUTec)

    2013-10-01

    A highly efficient utilisation of substrates and operational stability at the same time is essential for the efficiency of a biogas plant. The research project SequEx of HAWK and /SF GmbH investigates the increase of efficiency of biogas plants by targeted use of trace elements taking into account bio-availability. Based on sequential extraction diagrams a method for the determination of bio-availability of macro- and micro-nutrients is developed. Within this context, different trace element compounds are analysed during the fermentation process on their share of bioavailable micro-nutrients as well as their effect on the biological activity of microorganisms. The actual knowledge gap between common practice of nutrients' supply and real impact shall be closed by the knowledge base enhancement of the bio-availability of nutrients. (orig.)

  7. OMI NO2 in the Central US Great Plains: How Well Do We Interpret NO2 Trends?

    Science.gov (United States)

    Kollonige, D. E.; Duncan, B. N.; Thompson, A. M.; Lamsal, L. N.

    2017-12-01

    Several areas over the Central US show statistically significant increases in OMI NO2 levels of 10-30% in the last 10 years versus the generally decreasing trends over most of CONUS. Are these changes in OMI NO2 a result of human activity, meteorology, or a combination of both? To answer this, we examine regions in the Central US Great Plains that have multiple plausible sources for the observed trends, considering impacts of land surface changes, agriculture growth, oil and gas operations, and drought conditions. We find that changes to the land surface appear to contribute to some of the observed anomalies due to tree removal in the Black Hills National Forest, South Dakota, and additional livestock farming in the Sandhills of Nebraska. However, increasing OMI NO2 also corresponds to several areas with growing agriculture business (ex. South Dakota and Nebraska) and oil and gas activity (ex. Williston Basin in North Dakota and Permian Basin in TX). To understand the relationship between the observed NO2 variability and the regional meteorological conditions over the last decade, we analyze the time series and correlations between OMI NO2, NH3 (an agriculture tracer), surface temperature, normalized difference vegetation index (NDVI) from Landsat, and the Palmer Drought Severity Index (PDSI). In 2012, drought conditions affect NO2, NH3 and NDVI observations across the Central US. Areas where dryland farming and livestock grazing are predominant (Central SD, ND, KS, and NE) are less sensitive to drought and changes in temperature. This suggests positive OMI NO2 trends are caused by increased production in wheats and livestock in the Northern Great Plains. These study regions in the Central US, impacted by local emissions and meteorology, are valuable for evaluating future trend analyses including the continuation of OMI-type NO2 retrievals from the TROPOMI and TEMPO satellite instruments.

  8. NO2 Total and Tropospheric Vertical Column Densities from OMI on EOS Aura: Update

    Science.gov (United States)

    Gleason, J.F.; Bucsela, E.J.; Celarier, E.A.; Veefkind, J.P.; Kim, S.W.; Frost, G.F.

    2009-01-01

    The Ozone Monitoring Instrument (OMI), which is on the EOS AURA satellite, retrieves vertical column densities (VCDs) of NO2, along with those of several other trace gases. The relatively high spatial resolution and daily global coverage of the instrument make it particularly well-suited to monitoring tropospheric pollution at scales on the order of 20 km. The OMI NO2 algorithm distinguishes polluted regions from background stratospheric NO2 using a separation algorithm that relies on the smoothly varying stratospheric NO2 and estimations of both stratospheric and tropospheric air mass factors (AMFs). Version 1 of OMI NO2 data has been released for public use. An overview of OMI NO2 data, some recent results and a description of the improvements for version 2 of the algorithm will be presented.

  9. Global Trends of Tropospheric NO2 Observed From Space

    Science.gov (United States)

    Schneider, P.; van der A, R. J.

    2012-04-01

    Nitrogen Dioxide (NO2) is one of the major atmospheric pollutants and is primarily emitted by industrial activity and transport. While observations of NO2 are frequently being carried out at air quality stations, such measurements are not able to provide a global perspective of spatial patterns in NO2 concentrations and their associated trends due to the stations' limited spatial representativity and an extremely sparse and often completely non-existent station coverage in developing countries. Satellite observations of tropospheric NO2 are able to overcome this issue and provide an unprecedented global view of spatial patterns in NO2 levels and due to their homogeneity are well suited for studying trends. Here we present results of a global trend analysis from nearly a decade of NO2 observations made by the SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY) instrument onboard the Envisat satellite platform. Using only SCIAMACHY data allows for mapping global and regional trends at an unprecedented spatial resolution since no aggregation to the coarser resolution of other sensors is necessary. Monthly average tropospheric NO2 column data was acquired for the period between August 2002 and August 2011. A trend analysis was subsequently performed by fitting a statistical model including a seasonal cycle and linear trend to the time series extracted at each grid cell. The linear trend component and the trend uncertainty were then mapped spatially at both regional and global scales. The results show that spatially contiguous areas of significantly increasing NO2 levels are found primarily in Eastern China, with absolute trends of up to 4.05 (± 0.41) - 1015 molecules cm-2 yr-1 at the gridcell level and large areas showing rapid relative increases of 10-20 percent per year. In addition, many urban agglomerations in Asia and the Middle East similarly exhibit significantly increasing trends, with Dhaka in Bangladesh being the megacity with

  10. 21 CFR 74.102 - FD&C Blue No. 2.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false FD&C Blue No. 2. 74.102 Section 74.102 Food and... ADDITIVES SUBJECT TO CERTIFICATION Foods § 74.102 FD&C Blue No. 2. (a) Identity. (1) The color additive FD&C...-1H-indole-5-sulfonic acid (CAS Reg. No. 605-18-5). Additionally, FD&C Blue No. 2 is obtained by...

  11. Eddy Covariance Fluxes of the NO-O3-NO2 Triad above the Forest Canopy at the ATTO Site in the Amazon Basin

    Science.gov (United States)

    Tsokankunku, A.; Wolff, S.; Berger, M.; Zelger, M.; Dlugi, R. J. W.; Andreae, M. O.; Sörgel, M.

    2017-12-01

    Nitrogen monoxide (NO) and nitrogen dioxide (NO2) (denoted together as NOx) determine the abundance of the tropospheric oxidants OH, O3 and NO3 that regulate atmospheric self-cleaning. The three reactive trace gases NO, NO2 and O3 undergo a series of interconnected photochemical reactions and are therefore often referred to as the NO-O3-NO2 triad. Ozone deposition is mainly controlled by stomatal uptake, therefore resulting in oxidative stress for the plants. Similarly, nitrogen dioxide from above or below the canopy is deposited to leaves through stomatal uptake. NO emissions from soils contribute to above canopy O3 formation and accelerate OH recycling. Therefore, quantification of the biosphere-atmosphere exchange fluxes of these species is important for atmospheric chemistry and ecosystem research. The eddy covariance method is state of the art for direct measurements of ecosystem fluxes of trace gases. Eddy covariance measurements of NOx in pristine environments are rare because of lack of availability of instruments with the required precision to resolve concentrations characteristic of these environments with the required high time resolution. The Amazon Tall Tower Observatory (ATTO) is located in a pristine rainforest environment in the Amazon basin about 150 km northeast of the city of Manaus. It is the ideal site for studying the biosphere-atmosphere exchange of the NO-O3-NO2 triad, because of the absence of nearby anthropogenic sources. During an intensive measurement campaign in November 2015 at the ATTO site, measurements of NO, NO2 and O3 were carried out at 42 m above ground level on the 80 m walk-up tower with a fast (5 Hz) and sensitive (< 30 ppt) instrument (CLD790SR2, Eco Physics) for NO and NO2 and with 10 Hz for O3 (Enviscope GmbH). Additionally, a suite of micrometeorological instruments was installed, including a profile of 3-dimensional sonic anemometers and meteorological sensors. Vertical concentration profile measurements of NO, NO2 and O

  12. 21 CFR 74.3102 - FD&C Blue No. 2.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false FD&C Blue No. 2. 74.3102 Section 74.3102 Food and... ADDITIVES SUBJECT TO CERTIFICATION Medical Devices § 74.3102 FD&C Blue No. 2. (a) Identity. The color additive FD&C Blue No. 2 shall conform in identity to the requirements of § 74.102(a)(1). (b...

  13. 21 CFR 74.1102 - FD&C Blue No. 2.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false FD&C Blue No. 2. 74.1102 Section 74.1102 Food and... ADDITIVES SUBJECT TO CERTIFICATION Drugs § 74.1102 FD&C Blue No. 2. (a) Identity. (1) The color additive FD... mixtures for use in ingested drugs made with FD&C Blue No. 2 may contain only those diluents that are...

  14. Nördlinger Ries campaign on Soil Emissions (NORISE) - DOAS measurements of NO2 and HCHO in an agricultural region

    Science.gov (United States)

    Zörner, Jan; Remmers, Julia; Dörner, Steffen; Wang, Yang; Eger, Philipp; Pöhler, Dennis; Behrendt, Thomas; Meixner, Franz; Penning de Vries, Marloes; Wagner, Thomas

    2016-04-01

    Soil is a major source of total nitrogen oxide (NOx = NO + NO2) emissions with a fraction of about 15% on a global basis. Soil emissions, stemming from bacterial emissions of NO, are controlled by abiotic and microbiological processes which themselves depend on ambient environmental conditions like soil type, moisture content, temperature as well as agricultural management practices such as fertilization. In recent laboratory experiments it was found that dry soils also exhibit enhanced emissions of several volatile organic compounds (VOC) including HCHO when first wetted. At present, studies on soil emissions in humid climates are limited to point samples and laboratory measurements. Thus, a campaign was organized that is dedicated to the analysis of trace gases which are potentially emitted from soils over an entire area using ground based mini-MAX-DOAS measurements. Since soil emissions are assumed to be highest from lands predominantly used for agriculture, the Nördlinger Ries in Bavaria, Germany, a 25 km wide circular plain formed by a meteor impact about 14.5 million years ago, was chosen which nowadays is dominated by arable land. The main objective of the NORISE campaign was to characterize trace gas levels in a highly agricultural environment. The time frame, consequently, covered a whole growing season from April 2014 to January 2015. The focus was on trace gases which can be measured using the DOAS approach in the UV/VIS spectral range, i.e. NO2 and HCHO, using two mini-MAX-DOAS instruments and one long-path DOAS instrument. The retrieved NO2 and HCHO column densities were examined for long-term variations over the entire growing season and short-term events which are both linked to environmental conditions like precipitation patterns and temperature changes. In addition, the analysis of soil samples taken from fields, distinguished between organic and conventional cultivation, gives further insights into soil activities. In this work, we present

  15. JUST Vol. 28 No. 2 Aug 2008

    African Journals Online (AJOL)

    ben

    2008-08-02

    Aug 2, 2008 ... markets (Instituto de Energia Solar, 1998). Automotive SLI batteries, by their design, are not appropriate for solar PV applications. They have thin plates and can discharge high currents for short periods only. In addition, their charging requirements in PV applications are not well known and manufacturers ...

  16. Water SA - Vol 27, No 2 (2001)

    African Journals Online (AJOL)

    The use of simultaneous chemical precipitation in modified activated sludge systems exhibiting biological excess phosphate removal: Part 5: Experimental periods using ... Effect of PAC addition in combined treatment of landfill leachate and domestic wastewater in semi-continuously fed batch and continuous-flow reactors ...

  17. NO2 and Cancer Incidence in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Khalid Al-Ahmadi

    2013-11-01

    Full Text Available Air pollution exposure has been shown to be associated with an increased risk of specific cancers. This study investigated whether the number and incidence of the most common cancers in Saudi Arabia were associated with urban air pollution exposure, specifically NO2. Overall, high model goodness of fit (GOF was observed in the Eastern, Riyadh and Makkah regions. The significant coefficients of determination (r2 were higher at the regional level (r2 = 0.32–0.71, weaker at the governorate level (r2 = 0.03–0.43, and declined slightly at the city level (r2 = 0.17–0.33, suggesting that an increased aggregated spatial level increased the explained variability and the model GOF. However, the low GOF at the lowest spatial level suggests that additional variation remains unexplained. At different spatial levels, associations between NO2 concentration and the most common cancers were marginally improved in geographically weighted regression (GWR analysis, which explained both global and local heterogeneity and variations in cancer incidence. High coefficients of determination were observed between NO2 concentration and lung and breast cancer incidences, followed by prostate, bladder, cervical and ovarian cancers, confirming results from other studies. These results could be improved using individual explanatory variables such as environmental, demographic, behavioral, socio-economic, and genetic risk factors.

  18. Comparison of NO2 and HCHO Vertical Columns Over Mexico City from Ground and Space

    Science.gov (United States)

    Ojeda Lerma, Z.; Grutter, M.; Stremme, W.; Rivera, C.; Friedrich, M. M.; Bezanilla Morlot, A.

    2017-12-01

    Here we present the analysis of spectra measured by the MAX-DOAS (Multi Axis Differential Optical Absorption Spectroscopy) instruments, wich form part of a monitoring network located in the Mexico City Metropolitan Area (MCMA). The spectra are processed using the MMF (Mexican Maxdoas Fit) retrieval code which is based on least square fitting and uses optimal estimation and Tikhonov regularization for trace gas and aerosol retrieval, respectively. The retrieved vertical columns densities of NO2 and the methodology used for the statistical calculation of the errors are presented. We compare the NO2 vertical columns densities from the MAX-DOAS measurements with the tropospheric vertical columns from the OMI (Ozone Monitoring Instrument) satellite sensor, using both the DOMINO (Dutch OMI NO2) and the Standard Products V003. The variability observed in the time series of NO2 and HCHO are anlyzed in terms of known patterns of the emission sources, photochemistry and seasonality.

  19. Food irradiation newsletter. V. 17, no. 2

    International Nuclear Information System (INIS)

    1993-07-01

    This issue of the Food Irradiation Newsletter includes reports of a number of activities of the Food Preservation Section of the FAO/IAEA from the final quarter of 1992 to the middle of 1993. In addition there is a summary of food irradiation activities in the USA, an excerpt from the Official Gazette of the French Republic concerning the use of ionizing radiation to treat camembert made from raw milk, and a discussion of the potential for the application of food irradiation in Russia

  20. Mapping of the Tropospheric NO2 Spatial Distribution at City-scale Based on Airborne APEX Hyperspectral Imaging

    Science.gov (United States)

    Tack, F. M.; Merlaud, A.; Danckaert, T.; Yu, H.; Fayt, C.; Iordache, D.; Meuleman, K.; Fierens, F.; Deutsch, F.; Van Roozendael, M.

    2016-12-01

    NO2 is a key pollutant with highly variable concentrations in space and time. Quantitative information about its spatial variability at high resolution is currently scarce, but very valuable for (air quality) studies at the urban scale. APEX is a pushbroom hyperspectral imager with high spatial (60 by 80 m2) and spectral (2.8-3.3 nm) resolution. APEX flights were conducted over (1) the city and port of Antwerp, Belgium on April 14, 2015 and July 19, 2016, (2) Brussels, Belgium on June 30, 2015 (BUMBA project), and (3) Berlin, Germany on April 21, 2016 (AROMAT and AROMAPEX projects). APEX was operated from a DLR DO-228 plane at 6.1 km altitude. Over Berlin, two additional imagers, AirMAP (IUP Bremen) and SWING (BIRA-IASB), were simultaneously operated from a FUB Cessna at 3 km for intercomparison purposes. NO2 vertical column densities (VCDs) are retrieved based on (1) the DOAS analysis of the observed spectra in the visible region (470 nm - 510 nm), and (2) air mass factor calculations with the RTM VLIDORT 2.6. Results show that APEX is suitable (1) to detect the fast varying spectral signatures of a trace gas like NO2 and (2) to identify small scale gradients in the NO2 field and to resolve individual emission sources. Main NOx sources in the Antwerp area are related to (petro)chemical industry, while traffic emissions are dominant in Brussels. Over Berlin, 2 large industrial NO2 plumes are detected by all three imaging systems, crossing the city from west to east. The NO2 VCD levels range between 0.2 and 3.5 x 1016 molec cm-2. The typical detection limit for the APEX instrument is around 1.7 to 2.2 x 1015 molec cm-2. Correlation coefficients of 0.85 and slopes close to unity are obtained when compared to coincident car mobile-DOAS measurements. The NO2 retrieval algorithm, campaign results, and ongoing research concerning the comparison of the VCDs with in-situ surface concentrations and a high resolution (25 m) air quality model, i.e. RIO-IFDM, will be discussed.

  1. Interferences of commercial NO2 instruments in the urban atmosphere and in a smog chamber

    Directory of Open Access Journals (Sweden)

    J. Kleffmann

    2012-01-01

    Full Text Available Reliable measurements of atmospheric trace gases are necessary for both, a better understanding of the chemical processes occurring in the atmosphere, and for the validation of model predictions. Nitrogen dioxide (NO2 is a toxic gas and is thus a regulated air pollutant. Besides, it is of major importance for the oxidation capacity of the atmosphere and plays a pivotal role in the formation of ozone and acid precipitation. Detection of NO2 is a difficult task since many of the different commercial techniques used are affected by interferences. The chemiluminescence instruments that are used for indirect NO2 detection in monitoring networks and smog chambers use either molybdenum or photolytic converters and are affected by either positive (NOy or negative interferences (radical formation in the photolytic converter. Erroneous conclusions on NO2 can be drawn if these interferences are not taken into consideration. In the present study, NO2 measurements in the urban atmosphere, in a road traffic tunnel and in a smog-chamber using different commercial techniques, i.e. chemiluminescence instruments with molybdenum or photolytic converters, a Luminol based instrument and a new NO2-LOPAP, were compared with spectroscopic techniques, i.e. DOAS and FTIR. Interferences of the different instruments observed during atmospheric measurements were partly characterised in more detail in the smog chamber experiments. Whereas all the commercial instruments showed strong interferences, excellent agreement was obtained between a new NO2-LOPAP instrument and the FTIR technique for the measurements performed in the smog chamber.

  2. Effect of surfactant addition on ultrasonic leaching of trace elements from plant samples in inductively coupled plasma-atomic emission spectrometry

    Science.gov (United States)

    Borkowska-Burnecka, Jolanta; Jankowiak, Urszula; Zyrnicki, Wieslaw; Anna Wilk, Kazimiera

    2004-04-01

    The applicability of surfactants in sample preparation of plant materials followed by analysis by inductively coupled plasma atomic emission spectrometry has been examined. Reference materials (INCT-MPH-2-Mixed Polish Herbs, INCT-TL-1 black tea leaves and CTA-VTL-2 -Virginia tobacco leaves) and commercially available tea leaves were analyzed. Effects of addition surfactants (Triton X-100, didodecyldimethylammonium bromide and cetyltrimethylammonium bromide) on efficiency of ultrasonic leaching of elements from the plant samples and on plasma parameters were investigated. Low concentrations of the surfactants in solutions did not affect, in practice, analytical line intensities and the nebulization process. Quantitative recovery of some elements could be obtained by ultrasonic diluted acid leaching with the aid of surfactants. However, the element recovery depended on type of surfactant, as well as element and sample material. Plasma parameters, i.e. the excitation temperatures of Ar I, Fe II and Ca II as well as the electron number density and the Mg II/Mg I intensity ratio did not vary significantly due to the surfactants in solutions.

  3. Remote sensing of stratospheric O3 and NO2 using a portable and compact DOAS spectrometer

    Science.gov (United States)

    Raponi, M. M.; Jiménez, R.; Wolfram, E.; Tocho, J. O.; Quel, E. J.

    2011-01-01

    The use of passive and active remote sensing systems has largely contributed to advance our understanding of important atmospheric phenomena. Here we present a compact and portable passive DOAS (Differential Optical Absorption Spectroscopy) system, developed for measuring the vertical column density (VCD) of multiple atmospheric trace gases. We highlight the main characteristics of the system components: a mini-spectrometer (HR4000, Ocean Optics), two optical fibers (400 μm of core, 6 m and 25 cm of longitude), an external shutter and the control/data processing software. Nitrogen dioxide (NO2) and ozone (O3) VCDs are derived from solar spectra acquired during twilights (87° - 91° zenithal angles) using the DOAS technique. The analysis is carried out by solving the Beer-Lambert-Bouger (BLB) law for the main atmospheric absorbers at selected wavelength ranges. The algorithm minimizes the fitting residuals to the BLB law, having as unknown the slant column density (SCD) of the species to determine. We present measurements carried out at the Marambio Antarctic Base (64° 14' 25'' S; 56° 37' 21'' W, 197 m asl) during January - February 2008. In addition, we compare our results with co-located measurements performed with EVA, a visible absorption spectrometer of Instituto Nacional de Técnica Aeroespacial (INTA, Spain), a Dobson spectrophotometer of Servicio Meteorológico Nacional (SMN, Argentine) and the Ozone Monitoring Instrument (OMI), on board AURA satellite.

  4. Soils newsletter. V. 21, no. 2

    International Nuclear Information System (INIS)

    1998-12-01

    This issue of the Soils Newsletter summarises the activities of the Soil and Water Management and Crop Nutrition Section of the IAEA during 1998. A total of six Research Co-ordination Meetings (RCMs) were held during 1998, four at HQ in Vienna, one in Bucharest, Romania, and one in Oeiras, Portugal. Of the meetings held at HQ, two were final meetings (CRPs on 'Irrigated Wheat' and 'Phosphatic Fertilizers'), while another was the first (CRP on 'Rainfed Agriculture'). A Consultants' Meeting was also held at HQ on 'The Comparison of Three Soil Water Content Assessment Methods'. Another significant meeting in 1998 was Workshop D at the 16th World Congress of Soil Science in Montpellier, France ('The Use of Nuclear Techniques for Developing Sustainable Soil, Water and Nutrient Management Practices') which was sponsored by the Joint FAO/IAEA Division. A Workshop or Symposium convened by the Sub-programme has become a regular event at the World Congress of Soil Science which is held every four years. Details of all Meetings are given in the Newsletter. Four RCMs are planned for 1999, one at HQ (first RCM in 'Agroforestry'), one in Barcelona, Spain (third RCM in 'Soil Erosion'), one in Rabat, Morocco (third RCM in 'Organic Matter') and one in Kuala Lumpur, Malaysia (final RCM in 'Irradiated Sewage Sludge'). In addition, a Consultants' Meeting to plan for a new CRP on 'Acid Soils' will be held in Vienna early in 1999. Detailed planning for an International Symposium on Nuclear Techniques for Developing Sustainable Soil, Water and Nutrient Management Practice, to be held at HQ in October 2000, will also be initiated early in 1999

  5. 21 CFR 82.102 - FD&C Blue No. 2.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false FD&C Blue No. 2. 82.102 Section 82.102 Food and... PROVISIONALLY LISTED COLORS AND SPECIFICATIONS Foods, Drugs, and Cosmetics § 82.102 FD&C Blue No. 2. The color additive FD&C Blue No. 2 shall conform in identity and specifications to the requirements of § 74.102(a)(1...

  6. A New Retrieval Algorithm for OMI NO2: Tropospheric Results and Comparisons with Measurements and Models

    Science.gov (United States)

    Swartz, W. H.; Bucesla, E. J.; Lamsal, L. N.; Celarier, E. A.; Krotkov, N. A.; Bhartia, P, K,; Strahan, S. E.; Gleason, J. F.; Herman, J.; Pickering, K.

    2012-01-01

    Nitrogen oxides (NOx =NO+NO2) are important atmospheric trace constituents that impact tropospheric air pollution chemistry and air quality. We have developed a new NASA algorithm for the retrieval of stratospheric and tropospheric NO2 vertical column densities using measurements from the nadir-viewing Ozone Monitoring Instrument (OMI) on NASA's Aura satellite. The new products rely on an improved approach to stratospheric NO2 column estimation and stratosphere-troposphere separation and a new monthly NO2 climatology based on the NASA Global Modeling Initiative chemistry-transport model. The retrieval does not rely on daily model profiles, minimizing the influence of a priori information. We evaluate the retrieved tropospheric NO2 columns using surface in situ (e.g., AQS/EPA), ground-based (e.g., DOAS), and airborne measurements (e.g., DISCOVER-AQ). The new, improved OMI tropospheric NO2 product is available at high spatial resolution for the years 200S-present. We believe that this product is valuable for the evaluation of chemistry-transport models, examining the spatial and temporal patterns of NOx emissions, constraining top-down NOx inventories, and for the estimation of NOx lifetimes.

  7. Rapid economic growth leads to boost in NO2 pollution over India, as seen from space

    Science.gov (United States)

    Hilboll, Andreas; Richter, Andreas; Burrows, John P.

    2016-04-01

    Over the past decades, the Indian economy has been growing at an exceptional pace. This growth was induced and accompanied by a strong increase of the Indian population. Consequently, traffic, electricity consumption, and industrial production have soared over the past decades, leading to a strong increase in fuel consumption and thus pollutant emissions. Nitrogen oxides (NO+NO2) are a major component of anthropogenic air pollution, playing key part in reaction cycles leading to the formation of tropospheric ozone. They are mainly emitted by the combustion of fossil fuels; other sources include production by lightning, biomass burning, and microbial activity in soils. Since the mid-1990s, space-borne measurements of tropospheric nitrogen dioxide (NO2) have been conducted by the GOME, SCIAMACHY, GOME-2, and OMI instruments. These instruments perform hyperspectral measurements of scattered and reflected sunlight. Their measurements are then analyzed using differential optical absorption spectroscopy (DOAS) to yield vertically integrated columnar trace gas abundances. Here, we will present the results of 20 years of NO2 measurements over the Indian subcontinent. After showing the spatial distribution of NO2 pollution over India, we will present time series for individual states and urban agglomerations. These time series will then be related to various indicators of economic development. Finally, we will highlight several instances where single industrial pollution sources and their development can clearly be identified from the NO2 maps and estimate their NO2 emissions.

  8. Svendsen Symphony No. 2 in B flat / Robert Layton

    Index Scriptorium Estoniae

    Layton, Robert

    1994-01-01

    Uuest heliplaadist "Svendsen Symphony No. 2 in B flat, Op. 15... Stavanger Symphony Orchestra / Grant Llewellyn. Chatsworth CD FCM 1002; Symphony No. 2 - selected comparisons: Gothenburg SO, Järvi (11/87)(BIS) CD 347

  9. Changes in SO2 and NO2 Pollution over the Past Decade Observed by Aura OMI

    Science.gov (United States)

    Krotkov, N. A.; Li, C.; Lamsal, L. N.; Celarier, E. A.; Marchenko, S. V.; Swartz, W.; Bucsela, E. J.; Fioletov, V.; McLinden, C. A.; Joiner, J.; Bhartia, P. K.; Duncan, B. N.; Dickerson, R. R.

    2014-12-01

    The Ozone Monitoring Instrument (OMI), a NASA partnership with the Netherlands and Finland, flies on the EOS Aura satellite and uses reflected sunlight to measure two critical atmospheric trace gases, nitrogen dioxide (NO2) and sulfur dioxide (SO2), characterizing daily air quality. Both gases and the secondary pollutants they produce (particulate matter, PM2.5, and tropospheric ozone) are among USEPA designated criteria pollutants, posing serious threats to human health and the environment (e.g., acid rain, plant damage, and reduced visibility). A new generation of the OMI standard SO2 and NO2 products (based on critically improved DOAS spectral fitting for NO2 and innovative Principal Component Analysis method for SO2) provides a valuable dataset for studying anthropogenic pollution on local to global scales. Here we highlight some of the OMI observed long-term changes in air quality over several regions. Over the US, average NO2 and SO2 pollution levels have decreased dramatically as a result of both technological improvements (e.g., catalytic converters on cars) and stricter regulations of emissions. We see continued decline in NO2 and SO2 pollution over Europe. Over China OMI observed a ~ 60% increase in NO2 pollution between 2005 and 2013, despite a temporary reversal of the growing trend due to both 2008 Olympic Games and the economic recession in 2009. Chinese SO2 pollution seems to have stabilized since peaking in 2007, probably due to government efforts to curb SO2 emissions from the power sector. We have also observed large increases in both SO2 and NO2 pollution particularly in Eastern India where a number of new large coal power plants have been built in recent years. We expect that further improvements in the OMI NO2 and SO2 products will allow more robust quantification of long-term trends in local to global air quality.

  10. Horizontal and temporal evolution of tropospheric NO2 in Vienna as inferred from car DOAS measurements

    Science.gov (United States)

    Schreier, Stefan F.; Richter, Andreas; Li, Zheng; Burrows, John P.

    2016-04-01

    Zenith-sky measurements were performed with a car DOAS (Differential Optical Absorption Spectroscopy) instrument to obtain tropospheric nitrogen dioxide (NO2) distributions within the metropolitan area of Vienna, Austria, on nine days in April, September, October, and November 2015. Several single car journeys having an approximate distance of 110 km and covering known emission sources of nitrogen oxides (NOx) as well as a background region north of Vienna were carried out. The spectral measurements are analyzed using the DOAS technique applying a nonlinear least-squares fitting algorithm. The obtained NO2 differential slant column densities (DSCDs) are based on the 425-490 nm fitting window and the inclusion of relevant high resolution absorption cross-sections. Tropospheric NO2 vertical column densities (VCDs) are extracted from the NO2 DSCDs by making assumptions on the diurnal variation of stratospheric NO2 VCDs and determining a tropospheric NO2 airmass factor. Additional meteorological (wind speed and wind direction) and air quality (surface NO2 concentrations) data from nearby measurement stations is used to interpret the horizontal and temporal evolution of NO2 pollution. Our results show that elevated NO2 pollution originating from rush-hour traffic over busy highways is transported along the Danube River to the Northwest of Vienna under certain meteorological conditions.

  11. Ignition-promoting effect of NO2 on methane, ethane and methane/ethane mixtures in a rapid compression machine

    DEFF Research Database (Denmark)

    Gersen, S.; Mokhov, A.V.; Darmeveil, J.H.

    2011-01-01

    of replacing 10% methane by ethane. For NO2-containing mixtures, the model predicts the observed trend in decreasing delay time with increasing NO2 fraction. However, the computations tend to overestimate the effect of NO2 addition on ignition, particularly for C2H6 mixtures. Analysis of the reaction mechanism...

  12. A comparison of NO2 absorption measurements from an FTIR spectrometer and the OSIRIS spectrograph

    International Nuclear Information System (INIS)

    Puckrin, E.; Evans, W.F.J.

    2007-01-01

    The optical spectrograph and infrared imager system (OSIRIS) aboard the Odin satellite was part of Canada's contribution to the international joint venture of this satellite project. OSIRIS is used for aeronomic studies, including the study of stratospheric ozone (O 3 ) depletion and transport dynamics. It collects limb-view spectra of the scattered sunlight in the ultraviolet-visible region and measures the column abundance of ozone, nitrogen dioxide (NO 2 ) and other trace constituents in the atmosphere. Vertical concentration profiles are then generated for these gases. In this study, spectral measurements of the transmission of a gas cell filled with various amounts of NO 2 were obtained with two instruments, a Fourier-transform infrared (FTIR) spectrometer and the OSIRIS spectrograph of the grating type. Five different gas-cell concentrations were examined in an effort to calibrate the OSIRIS instrument in the 400 to 700 nm region where NO 2 absorbs visible radiation. The NO 2 column amounts derived from the OSIRIS measurements ranged from 6.05 x 10 17 to 1.17 x 10 16 molecules/cm 2 , and agreed within 10 per cent of the values determined from the FTIR measurements. It was concluded that the OSIRIS spectrograph is well suited for the remote sensing of atmospheric NO 2 . 13 refs., 2 tabs., 5 figs

  13. Evaluation of a regional chemistry transport model using a newly developed regional OMI NO2 retrieval

    Science.gov (United States)

    Kuhlmann, G.; Lam, Y. F.; Cheung, H. M.; Hartl, A.; Fung, J. C. H.; Chan, P. W.; Wenig, M. O.

    2014-12-01

    In this paper, we evaluate a high-resolution chemistry transport model (CTM) (3 km x 3 km spatial resolution) with the new Hong Kong (HK) NO2 retrieval developed for the Ozone Monitoring Instrument (OMI) on-board the Aura satellite. The three-dimensional atmospheric chemistry was modelled in the Pearl River Delta (PRD) region in southern China by the Models-3 Community Multiscale Air Quality (CMAQ) modelling system from October 2006 to January 2007. In the HK NO2 retrieval, tropospheric air mass factors (AMF) were recalculated using high-resolution ancillary parameters of surface reflectance, NO2 profile shapes and aerosol profiles of which the latter two were taken from the CMAQ simulation. We also tested four different aerosol parametrizations. Ground level measurements by the PRD Regional Air Quality Monitoring (RAQM) network were used as additional independent measurements. The HK NO2 retrieval increases the NO2 vertical column densities (VCD) by (+31 ± 38) %, when compared to NASA's standard product (SP2), and reduces the mean bias (MB) between satellite and ground measurements by 26 percentage points from -41 to -15 %. The correlation coefficient r is low for both satellite datasets (r = 0.35) due to the high spatial variability of NO2 concentrations. The correlation between CMAQ and the RAQM network is low (r ≈ 0.3) and the model underestimates the NO2 concentrations in the north-western model domain (Foshan and Guangzhou). We compared the CMAQ NO2 time series of the two main plumes with our regional OMI NO2 product. The model overestimates the NO2 VCDs by about 15 % in Hong Kong and Shenzhen, while the correlation coefficient is satisfactory (r = 0.56). In Foshan and Guangzhou, the correlation is low (r = 0.37) and the model underestimates the VCDs strongly (MB = -40 %). In addition, we estimated that the OMI VCDs are also underestimated by about 10 to 20 % in Foshan and Guangzhou because of the influence of the model parameters on the AMF. In this study

  14. Obstetrics and Gynaecology Forum - Vol 12, No 2 (2002)

    African Journals Online (AJOL)

    Obstetrics and Gynaecology Forum - Vol 12, No 2 (2002). Journal Home > Archives > Vol 12, No 2 (2002). Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives. DOWNLOAD FULL ...

  15. 7 CFR 51.1002 - U.S. No. 2.

    Science.gov (United States)

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946.... No. 2 grade requirements only because of blanching shall be designated as “U.S. No. 2, Mixed Color...

  16. African Journal of Reproductive Health - Vol 4, No 2 (2000)

    African Journals Online (AJOL)

    African Journal of Reproductive Health. ... African Journal of Reproductive Health - Vol 4, No 2 (2000). Journal Home > Archives > Vol 4, No 2 (2000). Log in or Register to get access to full text downloads. ... Editorial: Female Genital Mutilation: A Model for Research on Sexual and Reproductive Rights. OA Olatunbosun ...

  17. 40 CFR 1065.376 - Chiller NO2 penetration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Chiller NO2 penetration. 1065.376... CONTROLS ENGINE-TESTING PROCEDURES Calibrations and Verifications Nox and N2o Measurements § 1065.376 Chiller NO2 penetration. (a) Scope and frequency. If you use a chiller to dry a sample upstream of a NOX...

  18. 7 CFR 51.686 - U.S. No. 2.

    Science.gov (United States)

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946....686 U.S. No. 2. “U.S. No. 2” consists of oranges which meet the following requirements: (a) Basic...

  19. Degenerate four-wave mixing and polarization spectroscopy in NO2

    Science.gov (United States)

    De Dominicis, Luigi; Fantoni, Roberta; Giorgi, Mariano

    2002-05-01

    Degenerate Four Wave Mixing (DFWM) and polarization spectroscopy (PS) have been used to detect traces of nitric dioxide in a static cell at room temperature and in a small flame from a laboratory Bunsen burner. The high resolution spectrum of the Douglas-Huber band has been recorded with both techniques. The role played by population and thermal gratings in the DFWM case has been investigated under various experimental conditions. PS measurements performed with 'orientation' and 'alignment' configurations allowed to resolve NO2 composite spectral features.

  20. Sb-SnO2-Nanosized-Based Resistive Sensors for NO2 Detection

    Directory of Open Access Journals (Sweden)

    T. Krishnakumar

    2009-01-01

    Full Text Available A study over Sb-promoted tin oxide nanopowders for sensing applications is reported. SnO2 nanopowders pure and promoted with 5 wt% of antimony were prepared by wet chemical methods and widely characterized by TEM, XRD, and XPS techniques. Thick film resistive sensors were fabricated by depositing the synthesized nanopowders by drop-coating on interdigited alumina substrates. The sensing characteristics of the pure SnO2 and Sb-promoted sensors for the monitoring of trace level of NO2 were studied. The response of the sensors to water vapor was also investigated, revealing that Sb acts favorably eliminating the interference of humidity.

  1. Highly resolved global distribution of tropospheric NO2 using GOME narrow swath mode data

    Directory of Open Access Journals (Sweden)

    S. Beirle

    2004-01-01

    Full Text Available The Global Ozone Monitoring Experiment (GOME allows the retrieval of tropospheric vertical column densities (VCDs of NO2 on a global scale. Regions with enhanced industrial activity can clearly be detected, but the standard spatial resolution of the GOME ground pixels (320x40km2 is insufficient to resolve regional trace gas distributions or individual cities. Every 10 days within the nominal GOME operation, measurements are executed in the so called narrow swath mode with a much better spatial resolution (80x40km2. We use this data (1997-2001 to construct a detailed picture of the mean global tropospheric NO2 distribution. Since - due to the narrow swath - the global coverage of the high resolution observations is rather poor, it has proved to be essential to deseasonalize the single narrow swath mode observations to retrieve adequate mean maps. This is done by using the GOME backscan information. The retrieved high resolution map illustrates the shortcomings of the standard size GOME pixels and reveals an unprecedented wealth of details in the global distribution of tropospheric NO2. Localised spots of enhanced NO2 VCD can be directly associated to cities, heavy industry centers and even large power plants. Thus our result helps to check emission inventories. The small spatial extent of NO2 'hot spots' allows us to estimate an upper limit of the mean lifetime of boundary layer NOx of 17h on a global scale. The long time series of GOME data allows a quantitative comparison of the narrow swath mode data to the nominal resolution. Thus we can analyse the dependency of NO2 VCDs on pixel size. This is important for comparing GOME data to results of new satellite instruments like SCIAMACHY (launched March 2002 on ENVISAT, OMI (launched July 2004 on AURA or GOME II (to be launched 2005 with an improved spatial resolution.

  2. Satellite NO2 data improve national land use regression models for ambient NO2 in a small densely populated country

    NARCIS (Netherlands)

    Hoek, G.; Eeftens, M.; Beelen, R.; Fischer, P.; Brunekreef, B.; Boersma, K.F.; Veefkind, P.

    2015-01-01

    Land use regression (LUR) modelling has increasingly been applied to model fine scale spatial variation of outdoor air pollutants including nitrogen dioxide (NO2). Satellite observations of tropospheric NO2 improved LUR model in very large study areas, including Canada, United States and Australia.

  3. Satellite NO2 data improve national land use regression models for ambient NO2 in a small densely populated country

    NARCIS (Netherlands)

    Hoek, Gerard; Eeftens, Marloes; Beelen, Rob; Fischer, Paul; Brunekreef, Bert; Boersma, K. Folkert; Veefkind, Pepijn

    Land use regression (LUR) modelling has increasingly been applied to model fine scale spatial variation of outdoor air pollutants including nitrogen dioxide (NO2). Satellite observations of tropospheric NO2 improved LUR model in very large study areas, including Canada, United States and Australia.

  4. Trend analysis of urban NO2 concentrations and the importance of direct NO2 emissions versus ozone/NOx equilibrium

    NARCIS (Netherlands)

    Keuken, M.; Roemer, M.; Elshout, S. van den

    2009-01-01

    The annual air quality standard of NO2 is often exceeded in urban areas near heavy traffic locations. Despite significant decrease of NOx emissions in 1986-2005 in the industrial and harbour area near Rotterdam, NO2 concentrations at the urban background remain at the same level since the end of the

  5. Absorption of atmospheric NO2 by plants and soils, (1)

    International Nuclear Information System (INIS)

    Matsumaru, Tsuneo; Shiratori, Koji; Yoneyama, Tadakatsu; Totsuka, Tsumugu.

    1979-01-01

    Tomato, sunflower and corn plants were grown in culture solution containing three different concentrations of 15 N-labelled KNO 3 (260 ppm N, 105 ppm N, and 26 ppm N) as a nitrogen nutrient, and fumigated with 0.3 ppm NO 2 for 2 weeks during their vegetative stages. The amount of NO 2 nitrogen absorbed into the plants was estimated by ''difference method'' and '' 15 N method.'' '' 15 N method'' was found to give more probable values than ''difference method.'' According to '' 15 N method,'' the nitrogen derived from NO 2 was about 16% (tomato), 22% (sunflower), and 14% (corn) of the increased amount of total nitrogen in the whole plants in the 105 ppm N plot, and these percentages increased in the 26 ppm N plot. Difference in nitrogen concentration of the culture solution resulted in big change in the dry-weight increase of the tomato and sunflower plants, but the absorption rate of NO 2 nitrogen based on the dry weight changed slightly. The absorption rate of NO 2 nitrogen was around 0.8 mg (gDW) -1 day -1 in tomato and sunflower plants, and 0.3 mg (gDW) -1 day -1 in corn plant. Leaves were found to be an active sink of NO 2 and the nitrogen of NO 2 seemed to be rapidly transformed into compounds of high molecules in the leaf cells. (author)

  6. NO2 possible effects on human health in French Guiana

    Science.gov (United States)

    Gobinddass, Marie-Line; Dendele, Beatrice; Molinie, Jack; panechou-pulcherie, Kathy; Gatineau, Alexandre

    2016-04-01

    The International Agency for Research on Cancer (IARC) recently declared air pollution carcinogenic to humans. Humans are continuously exposed to nitrogen dioxide (NO2) emissions, a strong oxidizing pollutant commonly found in urban air and homes with unvented combustion appliances. Children and Individuals with asthma have been reported to be more sensitive to NO2exposure. Long-term exposure to NO2 pollution has been reported to induce defective pulmonary function, inflammation, irritations, respiratory infections like bronchitis, lung fibrosis, asthma exacerbation and an increase in inhalational allergies. Pollution peaks are responsible for older people premature death in city. According to W H O guideline values for NO2 emissions, a 1-hour level of 200 μg/m3 (0.1 ppm) and daily annual average of 40 μg/m3 (0.02 ppm) can be a real danger to human health. In general, current exposures in Europe are below this range. However, climate warming changes NO2 emissions and can become a real public health problem in few years. We will study here the temporal series of NO2 variation from data measurement campaigns of 2010 and 2014 in Cayenne city, the French Guiana capital. In this urban zone, NO2 is mainly created by cars traffic. Only 40% comes from combustion in thermal electric plan. A statistical approach will be used to compare NO2 Cayenne level to the daily and the annual threshold. Finally the NO2 evolution related to the climate warming and the growth of road traffic in French Guiana for the next year will be discussed.

  7. Characterization of tellurium-based films for NO2 detection

    International Nuclear Information System (INIS)

    Tsiulyanu, D.; Tsiulyanu, A.; Liess, H.-D.; Eisele, I.

    2005-01-01

    Sensing characteristics of tellurium-based thin films for NO 2 monitoring was studied systematically. The influence of contact materials, thermal treatment, temperature and thickness of the samples on the electrical conductivity and sensitivity to NO 2 with respect to scanning electron microscopy analyses is given. The possibility is shown to optimize the properties of the films for the development of a simple and stable NO 2 sensor device with rapid response/recovery time and low operating temperature. The sensing mechanism is discussed for the direct interaction of gaseous species with lone-pair electrons of chalcogen atoms

  8. Current Status of Post-combustor Trace Chemistry Modeling and Simulation at NASA Glenn Research Center

    Science.gov (United States)

    Wey, Thomas; Liu, Nan-Suey

    2003-01-01

    The overall objective of the current effort at NASA GRC is to evaluate, develop, and apply methodologies suitable for modeling intra-engine trace chemical changes over post combustor flow path relevant to the pollutant emissions from aircraft engines. At the present time, the focus is the high pressure turbine environment. At first, the trace chemistry model of CNEWT were implemented into GLENN-HT as well as NCC. Then, CNEWT, CGLENN-HT, and NCC were applied to the trace species evolution in a cascade of Cambridge University's No. 2 rotor and in a turbine vane passage. In general, the results from these different codes provide similar features. However, the details of some of the quantities of interest can be sensitive to the differences of these codes. This report summaries the implementation effort and presents the comparison of the No. 2 rotor results obtained from these different codes. The comparison of the turbine vane passage results is reported elsewhere. In addition to the implementation of trace chemistry model into existing CFD codes, several pre/post-processing tools that can handle the manipulations of the geometry, the unstructured and structured grids as well as the CFD solutions also have been enhanced and seamlessly tied with NCC, CGLENN-HT, and CNEWT. Thus, a complete CFD package consisting of pre/post-processing tools and flow solvers suitable for post-combustor intra-engine trace chemistry study is assembled.

  9. Raid, Kaljo: Symphony No. 2, "Stockholm" / Guy S. Rickards

    Index Scriptorium Estoniae

    Rickards, Guy S.

    1996-01-01

    Uuest heliplaadist "Raid, Kaljo: Symphony No. 2, "Stockholm"; Tubin, Eduard: Elegy for Strings (arr. Raid). Symphony No. 11 (orch. Raid). Estonian State Symphony Orchestra, Arvo Volmer". Koch International Classics 37291-2 (48 minutes:DDD)

  10. TES/Aura L2 NO2 Limb V006

    Data.gov (United States)

    National Aeronautics and Space Administration — The TES Aura L2 NO2 data consist of information for one molecular species for an entire Global Survey or Special Observation. TES Level 2 data contain retrieved...

  11. Power Company No 2. Activity Report 1992 - 1994

    International Nuclear Information System (INIS)

    1995-01-01

    The Power Company No.2 is in charge of power generation and distribution for the southern area of Vietnam. Status and development plans of the Company is presented in the report. (NHA). 10 figs, 2 tabs, 17 photos, 2 maps

  12. Fieldable, Real-Time NO2 Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovative Research Phase I proposal seeks to develop a compact, autonomous NO2 sensor for air monitoring applications based on laser induced...

  13. Bio-Research - Vol 7, No 2 (2009)

    African Journals Online (AJOL)

    Analysis of Different Brands of Fruit Juice with Emphasis on their Sugar and Trace Metal Content · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT ... Evaluation of the In-Vitro Combined Antimicrobial Activities of Garcinia kola Heckel and Honey · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL ...

  14. NO2 DOAS Measurements of Traffic Emissions by Chasing Cars

    Science.gov (United States)

    Zhu, Ying; Lipkowitsch, Ivo; Chan, Ka Lok; Bräu, Melanie; Wenig, Mark

    2016-04-01

    On this poster we present NO2 measurements using a Cavity-Enhanced DOAS on a measurement bus which we used to chase other vehicles to measure their NO2 emissions. Emissions of nitrogen oxides from on-road vehicles have received highly attention recently due to the increasing trend of ambient NOx level. It is particularly important to identify and quantify the direct emission and secondary formation of NO2 contributed by traffic emissions, in order to study the impact to the local air quality. We sampled on-road emissions in different environments and different driving conditions (e.g. urban, highway, different speeds). We analyse the data set in terms of spatial and temporal variability to search for temporal and spatial patterns. We present mean values sorted for different vehicle types, distance to the target car and travelling speeds to provide an emission data base from this measurement study.

  15. Electron transport in NH3/NO2 sensed buckled antimonene

    Science.gov (United States)

    Srivastava, Anurag; Khan, Md. Shahzad; Ahuja, Rajeev

    2018-04-01

    The structural and electronic properties of buckled antimonene have been analysed using density functional theory based ab-initio approach. Geometrical parameters in terms of bond length and bond angle are found close to the single ruffle mono-layer of rhombohedral antimony. Inter-frontier orbital analyses suggest localization of lone pair electrons at each atomic centre. Phonon dispersion along with high symmetry point of Brillouin zone does not signify any soft mode. With an electronic band gap of 1.8eV, the quasi-2D nano-surface has been further explored for NH3/NO2 molecules sensing and qualities of interaction between NH3/NO2 gas and antimonene scrutinized in terms of electronic charges transfer. A current-voltage characteristic has also been analysed, using Non Equilibrium Green's function (NEGF), for antimonene, in presence of incoming NH3/NO2 molecules.

  16. KONTRIBUSI PARAMETER METEOROLOGI DAN KONDISI LALU LINTAS TERHADAP KONSENTRASI PENCEMAR NO2 DI KOTA SEMARANG

    Directory of Open Access Journals (Sweden)

    Titik Istirokhatun

    2016-09-01

    Full Text Available Air pollution and its public health effects are drawing increasing concern from the environmental health research community, environmental regulatory agencies, industries as well as public. Nitrogen dioxide (NO2 is one of those common air pollutants that potentially major cause health problems. Transportation contributed most of the air pollution. In addition, the number of vehicles that are passing and queuing on the crossroads because of traffic light can affect the concentration of NO2. Besides, in these places there are a lot of road users which are potentially exposed by contaminants, so information about the concentration of NO2 on road side is important to know. This study aimed to investigate the impact of meteorological factors and the number of vehicles on NO2 concentrations. Impinger fritted bubler was used for air sampling, and Griess Saltzman method was used for determining NO2 concentration. Sampling and calculation of the number of passing vehicles were performed 3 times ie in the morning, afternoon and evening. Based on the results of the study, the highest concentrations of NO2 were on the range of 0.7-4.2 mg/Nm3.

  17. Measurements of peroxyacetyl nitrate (PAN) and NO2 at the South Pacific Ocean

    Science.gov (United States)

    Yeon, J.; Song, D.; Lee, J. S.; Rhee, T. S.; Park, K.; Lee, G.

    2014-12-01

    We measured peroxyacetyl nitrate (PAN) and NO2 in remote marine boundary area during the SHIPPO (Shipborne Pole to Pole Observation). The measurements were made on the R/V Araon from Christ church, New Zealand to Gwangyang, South Korea along the western Pacific Ocean from March 30th to April 25th, 2014. Both PAN and NO2 were analyzed every 2 minute by a fast chromatograph with luminol-based chemiluminescence detection. In order to improve their detection limits, random noise from PMT has been successfully reduced by ensembled chromatograms with every 30 samples. Additionally, we replaced Nylon membrane surface with reflective aluminum surface and applied the new Luminol solution, which enhanced the signals significantly with detection limits of 6 pptv and 40 ppbv for PAN and NO2, respectively. Average concentrations of PAN and NO2 were 8 pptv for PAN and 80 pptv for NO2 during the experiment. The back trajectory analysis showed that the directly influenced air masses from anthropogenic activities were rare except the latitudes higher than 20°N. Relatively good correlations between PAN and NO2 were consistently observed, while PAN and O3 were not clearly correlated except in the air masses recently originated from land masses.

  18. Aura OMI Observations of Global SO2 and NO2 Pollution from 2005 to 2013

    Science.gov (United States)

    Krotkov, Nickolay; Li, Can; Lamsal, Lok; Celarier, Edward; Marchenko, Sergey; Swartz, William H.; Bucsela, Eric; Fioletov, Vitali; McLinden, Chris; Joiner, Joanna; hide

    2014-01-01

    The Ozone Monitoring Instrument (OMI), a NASA partnership with the Netherlands and Finland, flies on the NASA Aura satellite and uses reflected sunlight to measure the two critical atmospheric trace gases: nitrogen dioxide (NO2) and sulfur dioxide (SO2) characterizing daily air quality. Both gases and the secondary pollutants they produce (particulate matter, PM2.5, and tropospheric ozone) are USEPA designated criteria pollutants, posing serious threats to human health and the environment (e.g., acid rain, plant damage and reduced visibility). Our group at NASA GSFC has developed and maintained OMI standard SO2 and NO2 data products. We have recently released an updated version of the standard NO2 L2 and L3 products (SP v2.1) and continue improving the algorithm. We are currently in the process of releasing next generation pollution SO2 product, based on an innovative Principal Component Analysis (PCA) algorithm, which greatly reduces the noise and biases. These new standard products provide valuable datasets for studying anthropogenic pollution on local to global scales. Here we highlight some of the OMI observed changes in air quality over several regions. Over the US average NO2 and SO2 pollution levels had decreased dramatically as a result of both technological improvements (e.g., catalytic converters on cars) and stricter regulations of emissions. We see continued decline in pollution over Europe. Over China OMI observed an increase of about 60 percent in NO2 pollution between 2005 and 2013, despite a temporal reversal of the growing trend due to both 2008 Olympic Games and the economic recession in 2009. Chinese SO2 pollution seems to have stabilized since peaking in 2007, probably due to government efforts to curb SO2 emissions from the power sector. We have also observed large increases in both SO2 and NO2 pollution particularly in Eastern India where a number of large new coal power plants had been built in recent years. We expect that further

  19. Comparison of methods for the determination of NO-O3-NO2 fluxes and chemical interactions over a bare soil

    Directory of Open Access Journals (Sweden)

    A. Mellouki

    2012-06-01

    Full Text Available Tropospheric ozone (O3 is a known greenhouse gas responsible for impacts on human and animal health and ecosystem functioning. In addition, O3 plays an important role in tropospheric chemistry, together with nitrogen oxides. The determination of surface-atmosphere exchange fluxes of these trace gases is a prerequisite to establish their atmospheric budget and evaluate their impact onto the biosphere. In this study, O3, nitric oxide (NO and nitrogen dioxide (NO2 fluxes were measured using the aerodynamic gradient method over a bare soil in an agricultural field. Ozone and NO fluxes were also measured using eddy-covariance and automatic chambers, respectively. The aerodynamic gradient measurement system, composed of fast response sensors, was capable to measure significant differences in NO and O3 mixing ratios between heights. However, due to local advection, NO2 mixing ratios were highly non-stationary and NO2 fluxes were, therefore, not significantly different from zero. The chemical reactions between O3, NO and NO2 led to little ozone flux divergence between the surface and the measurement height (less than 1% of the flux on average, whereas the NO flux divergence was about 10% on average. The use of fast response sensors allowed reducing the flux uncertainty. The aerodynamic gradient and the eddy-covariance methods gave comparable O3 fluxes. The chamber NO fluxes were down to 70% lower than the aerodynamic gradient fluxes, probably because of either the spatial heterogeneity of the soil NO emissions or the perturbation due to the chamber itself.

  20. Ebonyi Medical Journal - Vol 10, No 2 (2011)

    African Journals Online (AJOL)

    Ebonyi Medical Journal - Vol 10, No 2 (2011). Journal Home ... How Many Physicians Prescribe Quinine For The Treatment Of Malaria In The First Trimester Of Pregnancy? EMAIL FULL TEXT EMAIL ... Case report - Lassa Fever Mimicking Ectopic Pregnancy: A Report Of Three Cases · EMAIL FULL TEXT EMAIL FULL TEXT

  1. The version 3 OMI NO2 standard product

    Directory of Open Access Journals (Sweden)

    N. A. Krotkov

    2017-09-01

    Full Text Available We describe the new version 3.0 NASA Ozone Monitoring Instrument (OMI standard nitrogen dioxide (NO2 products (SPv3. The products and documentation are publicly available from the NASA Goddard Earth Sciences Data and Information Services Center (https://disc.gsfc.nasa.gov/datasets/OMNO2_V003/summary/. The major improvements include (1 a new spectral fitting algorithm for NO2 slant column density (SCD retrieval and (2 higher-resolution (1° latitude and 1.25° longitude a priori NO2 and temperature profiles from the Global Modeling Initiative (GMI chemistry–transport model with yearly varying emissions to calculate air mass factors (AMFs required to convert SCDs into vertical column densities (VCDs. The new SCDs are systematically lower (by ∼ 10–40 % than previous, version 2, estimates. Most of this reduction in SCDs is propagated into stratospheric VCDs. Tropospheric NO2 VCDs are also reduced over polluted areas, especially over western Europe, the eastern US, and eastern China. Initial evaluation over unpolluted areas shows that the new SPv3 products agree better with independent satellite- and ground-based Fourier transform infrared (FTIR measurements. However, further evaluation of tropospheric VCDs is needed over polluted areas, where the increased spatial resolution and more refined AMF estimates may lead to better characterization of pollution hot spots.

  2. Benchmark Simulation Model No 2 in Matlab-Simulink

    DEFF Research Database (Denmark)

    Vrecko, Darko; Gernaey, Krist; Rosen, Christian

    2006-01-01

    In this paper, implementation of the Benchmark Simulation Model No 2 (BSM2) within Matlab-Simulink is presented. The BSM2 is developed for plant-wide WWTP control strategy evaluation on a long-term basis. It consists of a pre-treatment process, an activated sludge process and sludge treatment...

  3. The version 3 OMI NO2 standard product

    Science.gov (United States)

    Krotkov, Nickolay A.; Lamsal, Lok N.; Celarier, Edward A.; Swartz, William H.; Marchenko, Sergey V.; Bucsela, Eric J.; Chan, Ka Lok; Wenig, Mark; Zara, Marina

    2017-09-01

    We describe the new version 3.0 NASA Ozone Monitoring Instrument (OMI) standard nitrogen dioxide (NO2) products (SPv3). The products and documentation are publicly available from the NASA Goddard Earth Sciences Data and Information Services Center (https://disc.gsfc.nasa.gov/datasets/OMNO2_V003/summary/). The major improvements include (1) a new spectral fitting algorithm for NO2 slant column density (SCD) retrieval and (2) higher-resolution (1° latitude and 1.25° longitude) a priori NO2 and temperature profiles from the Global Modeling Initiative (GMI) chemistry-transport model with yearly varying emissions to calculate air mass factors (AMFs) required to convert SCDs into vertical column densities (VCDs). The new SCDs are systematically lower (by ˜ 10-40 %) than previous, version 2, estimates. Most of this reduction in SCDs is propagated into stratospheric VCDs. Tropospheric NO2 VCDs are also reduced over polluted areas, especially over western Europe, the eastern US, and eastern China. Initial evaluation over unpolluted areas shows that the new SPv3 products agree better with independent satellite- and ground-based Fourier transform infrared (FTIR) measurements. However, further evaluation of tropospheric VCDs is needed over polluted areas, where the increased spatial resolution and more refined AMF estimates may lead to better characterization of pollution hot spots.

  4. Afican Health Sciences Vol 10 No 2.pmd

    African Journals Online (AJOL)

    Administrator

    African Health Sciences Vol 10 No 2 June 2010. 172. Indoor air mycoflora of residential dwellings in Jos metropolis. *Ayanbimpe GM1, Wapwera SD3, Kuchin D3. 1 Department of Medical Microbiology, University of Jos, Plateau State Nigeria,. 2 Department of Geography and Planning, University of Jos, Plateau State ...

  5. Tribromoisocyanuric Acid/NaNO 2 : a New Reagent for ...

    African Journals Online (AJOL)

    Nitrophenols can be obtained via direct nitration of phenols with tribromoisocyanuric acid,NaNO2 and wet SiO2 at room temperature in good to high yields. KEYWORDS: Tribromoisocyanuric acid, nitrophenols, heterogeneous conditions, sodium nitrite, nitration of phenols.

  6. Ghana Medical Journal - Vol 47, No 2 (2013)

    African Journals Online (AJOL)

    Ghana Medical Journal - Vol 47, No 2 (2013). Journal Home > Archives ... DOWNLOAD FULL TEXT. AB Olokoba, W Gashau, S Bwala, A Adamu, FK Salawu, 79-81 ... DOWNLOAD FULL TEXT. EY Bonney, NA Addo, NAA Ntim, F Addo-Yobo, P Bondzie, KE Aryee, J Barnor, J brandful, V Bekoe, SA Ohene, W Ampofo, 82-86 ...

  7. 75 FR 65471 - Combined Notice of Filings No. 2

    Science.gov (United States)

    2010-10-25

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Combined Notice of Filings No. 2 Tuesday, September 7, 2010. Take notice that the Commission has received the following Natural Gas Pipeline Rate and... Tuesday, September 14, 2010. Docket Numbers: RP10-922-001. Applicants: Venice Gathering System, L.L.C...

  8. Mizan Law Review - Vol 5, No 2 (2011)

    African Journals Online (AJOL)

    Mizan Law Review - Vol 5, No 2 (2011) ... Ethiopian Law of International Carriage by Air: An Overview · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT ... Comment: Overview of the Core Changes in the New Ethiopian Urban Land Leasehold Proclamation · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  9. 7 CFR 51.2835 - U.S. No. 2.

    Science.gov (United States)

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946.... 2. U.S. No. 2 consists of onions which meet the following requirements: (a) Basic requirements: (1...

  10. APEX (Air Pollution Exercise) Volume 12: Developer's Manual No. 2.

    Science.gov (United States)

    Environmental Protection Agency, Research Triangle Park, NC. Office of Manpower Development.

    The Developer's Manual No. 2 is part of a set of 21 manuals (AA 001 009-001 029) used in APEX (Air Pollution Exercise), a computerized college and professional level "real world" game simulation of a community with urban and rural problems, industrial activities, and air pollution difficulties. The first two sections, which are the same in each of…

  11. Oscilloscope trace photograph digitizing system (TRACE)

    International Nuclear Information System (INIS)

    Richards, M.; Dabbs, R.D.

    1977-10-01

    The digitizing system allows digitization of photographs or sketches of waveforms and then the computer is used to reduce and analyze the data. The software allows for alignment, calibration, removal of baselines, removal of unwanted points and addition of new points which makes for a fairly versatile system as far as data reduction and manipulation are concerned. System considerations are introduced first to orient the potential user to the process of digitizing information. The start up and actual commands for TRACE are discussed. Detailed descriptions of each subroutine and program section are also provided. Three general examples of typical photographs are included. A partial listing of FAWTEK is made available. Once suitable arrays that contain the data are arranged, ''GO FA'' (active FAWTEK) and many mathematical operations to further analyze the data may be performed

  12. Comparison of GOME tropospheric NO2 columns with NO2 profiles deduced from ground-based in situ measurements

    Directory of Open Access Journals (Sweden)

    D. Schaub

    2006-01-01

    Full Text Available Nitrogen dioxide (NO2 vertical tropospheric column densities (VTCs retrieved from the Global Ozone Monitoring Experiment (GOME are compared to coincident ground-based tropospheric NO2 columns. The ground-based columns are deduced from in situ measurements at different altitudes in the Alps for 1997 to June 2003, yielding a unique long-term comparison of GOME NO2 VTC data retrieved by a collaboration of KNMI (Royal Netherlands Meteorological Institute and BIRA/IASB (Belgian Institute for Space Aeronomy with independently derived tropospheric NO2 profiles. A first comparison relates the GOME retrieved tropospheric columns to the tropospheric columns obtained by integrating the ground-based NO2 measurements. For a second comparison, the tropospheric profiles constructed from the ground-based measurements are first multiplied with the averaging kernel (AK of the GOME retrieval. The second approach makes the comparison independent from the a priori NO2 profile used in the GOME retrieval. This allows splitting the total difference between the column data sets into two contributions: one that is due to differences between the a priori and the ground-based NO2 profile shapes, and another that can be attributed to uncertainties in both the remaining retrieval parameters (such as, e.g., surface albedo or aerosol concentration and the ground-based in situ NO2 profiles. For anticyclonic clear sky conditions the comparison indicates a good agreement between the columns (n=157, R=0.70/0.74 for the first/second comparison approach, respectively. The mean relative difference (with respect to the ground-based columns is −7% with a standard deviation of 40% and GOME on average slightly underestimating the ground-based columns. Both data sets show a similar seasonal behaviour with a distinct maximum of spring NO2 VTCs. Further analysis indicates small GOME columns being systematically smaller than the ground-based ones. The influence of different shapes in the a

  13. Ignition-promoting effect of NO2 on methane, ethane and methane/ethane mixtures in a rapid compression machine

    NARCIS (Netherlands)

    Gersen, S.; Mokhov, A. V.; Darmeveil, J. H.; Levinsky, H. B.; Glarborg, P.

    2011-01-01

    Autoignition delay times of stoichiometric methane, ethane and methane/ethane mixtures doped with 100 and 270 ppm of NO2 have been measured in a RCM in the temperature range 900-1050 K and pressures from 25 to 50 bar. The measurements show that addition of NO2 to CH4/O-2/N-2/ Ar and

  14. SO2 and NO2 over major urban regions of India: a tempo-spatial perspective

    Science.gov (United States)

    Mallik, C.; Lal, S.

    2012-12-01

    Demographic projections show that by the year 2025, 16 of the world's 29 megacities will be located in Asia, many of which have very basic problems in terms of air quality. Apart from being home to a burgeoning population, these regions of the globe are also major players in atmospheric chemistry as a result of myriad emission patterns combined with intense photochemistry. Like most of these Asian megacities, fast-paced development in some of the Indian cities has ramifications in increased emissions from industrial and transport sectors. These emissions release sulfur dioxide (SO2) and nitrogen dioxide (NO2), in addition to several pollutants, into the ambient air and have the potential to impact the chemistry and radiative balance on a regional scale. Surface measurements of these two criteria pollutants by the Central Pollution Control Board (CPCB), India during 2005-2010 from 13 urban locations in India have been analyzed to get an insight into their temporal and spatial variability. Stations are chosen to represent the entire Indian region: Indo-Gangetic plain or 'IGP' (Jalandhar, Delhi, Kanpur, Durgapur, Kolkata, Guwahati), western India (Jodhpur, Ahmedabad, Surat), central India (Nagpur, Hyderabad) and southern India (Chennai, Trivandrum). The monthly averaged surface level SO2 and NO2 have also been compared with monthly columnar averages of these gases as detected by the Ozone monitoring Instrument (OMI) over these station grids. Mean SO2 concentrations are found to be the highest for Surat (7.5 ppbv), located in a highly industrialized region. Elevated levels of NO2, observed for Durgapur and Kolkata (31 ppbv each), are close to the 24-hour 'National Ambient Air Quality' standard (30 ppbv). The surface concentrations for both SO2 and NO2 concentrations are found to be the highest during winter. Columnar SO2 over many stations show a maximum during summer monsoon. For most IGP stations, columnar NO2 values are elevated during winter. Wavelet analyses

  15. Activated sludge model No. 2d, ASM2d

    DEFF Research Database (Denmark)

    Henze, M.

    1999-01-01

    The Activated Sludge Model No. 2d (ASM2d) presents a model for biological phosphorus removal with simultaneous nitrification-denitrification in activated sludge systems. ASM2d is based on ASM2 and is expanded to include the denitrifying activity of the phosphorus accumulating organisms (PAOs......). This extension of ASM2 allows for improved modeling of the processes, especially with respect to the dynamics of nitrate and phosphate. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved....

  16. Metastable states in NO2+ probed with Auger spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Püttner, R.; Sekushin, V.; Fukuzawa, H.; Uhlíková, T.; Špirko, Vladimír; Asahina, T.; Kuze, N.; Kato, H.; Hoshino, M.; Tanaka, H.; Thomas, T. D.; Kukk, E.; Tamenori, Y.; Kaindl, G.; Ueda, K.

    2011-01-01

    Roč. 13, č. 41 (2011), s. 18436-18446 ISSN 1463-9076 Grant - others:GA ČR(CZ) GP203/09/P306; GA AV ČR(CZ) IAA400400504; GA MŠk(CZ) LC06071 Program:IA; LC Institutional research plan: CEZ:AV0Z40550506 Keywords : NO2+metastable states * Auger spectroscopy * vibrational energies Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.573, year: 2011

  17. Comparison of SO2 and NO2 observations from OMI and OMPS from 2012 to 2016

    Science.gov (United States)

    Wang, Y.; Wang, J.; Xu, X.; Yang, K.

    2017-12-01

    Both Sulfur dioxide (SO2) and nitrogen dioxide (NO2) are precursors of PM2.5 which has significant impacts on human health. We compare observations from Ozone Monitoring Instrument (OMI) which has data gap due to row anomaly and Ozone Mapping Profiler Suite (OMPS) that is currently the only operational UV satellite sensor providing contiguous daily global coverage. In this study, we examine changes of SO2 and NO2 in several polluted regions and see both upward trends and downward trends in different areas but trends observed by the two sensors are consistent in general. Some of these upward and downward trends are associated with economic development and implementation of emission control policy. In addition, we analyzed probability distribution function of SO2 and NO2 from the two sensors and how row anomaly effect the intercomparison.

  18. Epidemic contact tracing via communication traces.

    Science.gov (United States)

    Farrahi, Katayoun; Emonet, Rémi; Cebrian, Manuel

    2014-01-01

    Traditional contact tracing relies on knowledge of the interpersonal network of physical interactions, where contagious outbreaks propagate. However, due to privacy constraints and noisy data assimilation, this network is generally difficult to reconstruct accurately. Communication traces obtained by mobile phones are known to be good proxies for the physical interaction network, and they may provide a valuable tool for contact tracing. Motivated by this assumption, we propose a model for contact tracing, where an infection is spreading in the physical interpersonal network, which can never be fully recovered; and contact tracing is occurring in a communication network which acts as a proxy for the first. We apply this dual model to a dataset covering 72 students over a 9 month period, for which both the physical interactions as well as the mobile communication traces are known. Our results suggest that a wide range of contact tracing strategies may significantly reduce the final size of the epidemic, by mainly affecting its peak of incidence. However, we find that for low overlap between the face-to-face and communication interaction network, contact tracing is only efficient at the beginning of the outbreak, due to rapidly increasing costs as the epidemic evolves. Overall, contact tracing via mobile phone communication traces may be a viable option to arrest contagious outbreaks.

  19. Epidemic contact tracing via communication traces.

    Directory of Open Access Journals (Sweden)

    Katayoun Farrahi

    Full Text Available Traditional contact tracing relies on knowledge of the interpersonal network of physical interactions, where contagious outbreaks propagate. However, due to privacy constraints and noisy data assimilation, this network is generally difficult to reconstruct accurately. Communication traces obtained by mobile phones are known to be good proxies for the physical interaction network, and they may provide a valuable tool for contact tracing. Motivated by this assumption, we propose a model for contact tracing, where an infection is spreading in the physical interpersonal network, which can never be fully recovered; and contact tracing is occurring in a communication network which acts as a proxy for the first. We apply this dual model to a dataset covering 72 students over a 9 month period, for which both the physical interactions as well as the mobile communication traces are known. Our results suggest that a wide range of contact tracing strategies may significantly reduce the final size of the epidemic, by mainly affecting its peak of incidence. However, we find that for low overlap between the face-to-face and communication interaction network, contact tracing is only efficient at the beginning of the outbreak, due to rapidly increasing costs as the epidemic evolves. Overall, contact tracing via mobile phone communication traces may be a viable option to arrest contagious outbreaks.

  20. Parametric Trace Slicing

    Science.gov (United States)

    Rosu, Grigore (Inventor); Chen, Feng (Inventor); Chen, Guo-fang; Wu, Yamei; Meredith, Patrick O. (Inventor)

    2014-01-01

    A program trace is obtained and events of the program trace are traversed. For each event identified in traversing the program trace, a trace slice of which the identified event is a part is identified based on the parameter instance of the identified event. For each trace slice of which the identified event is a part, the identified event is added to an end of a record of the trace slice. These parametric trace slices can be used in a variety of different manners, such as for monitoring, mining, and predicting.

  1. Strong deviations from the NO-NO2-O3 photostationary state in the Pearl River Delta: Indications of active peroxy radical and chlorine radical chemistry

    Science.gov (United States)

    Ma, Yufang; Lu, Keding; Chou, Charles C.-K.; Li, Xiaoqian; Zhang, Yuanhang

    2017-08-01

    Simultaneous measurements of meteorological data, trace gases, and volatile organic compounds were made in two regional sites, viz. Backgarden and Kaiping, in the Pearl River Delta (PRD) during summer and autumn, respectively. The strong deviations from the NO-NO2-O3 Photostationary State, quantified by the leighton ratios, are carefully deduced through a comprehensive data set consist of the high-quality measurements of NO, NO2, O3 and JNO2 as well as the peroxy radical measurements. This is the first report of the Leighton ratio in China, with relatively high recorded values of 2.3 ± 0.4 (Backgarden) and 3.1 ± 1.4 (Kaiping), suggesting a strongly oxidising atmosphere in the PRD, typical of the ozone pollution season. A sensitivity analysis using a zero-dimensional chemical box model based on the regional atmospheric chemistry mechanism, version 2 (RACM2) constrained by the experimental measurements, indicated that peroxy radicals account for 70 (Backgarden) and 66% (Kaiping) of the observed positive deviations from the NOx photostationary state (characterized by a Leighton ratio of 1) on average. We consider that the remaining deviations result from neglecting the effects of chlorine chemistry, so we introduced a Cl chemistry module into RACM2, and the modelled results for Cl were as follows: 4.7 × 10-4 pptv in Backgarden and 1.3 × 10-3 pptv in Kaiping; these results are lower than the Cl concentration derived from the NOx photostationary state. More work is required to confirm the role of additional peroxy radical sources at both high and low NOx regimes, as well as that of the halogen radicals, in perturbing the NO-NOx-O3 cycle, which would significantly enhance trace gas removal and photochemical ozone production.

  2. Determination of Ultra-Trace Amounts of Selenium(IV) by Flow Injection Hydride Generation Atomic Absorption Spectrometry with On-line Preconcentration by Co-precipitation with Lanthanium Hydroxide. Part II. On-line Addition of Coprecipating Agent

    DEFF Research Database (Denmark)

    Nielsen, Steffen; Sloth, Jens Jørgen; Hansen, Elo Harald

    1996-01-01

    A flow injection procedure for the determination of ultra-trace amounts of selenium(IV) is described, which combines hydride generation atomic absorption spectrometry (HGAAS) with on-line preconcentration of the analyte by co-precipitation-dissolution in a filterless knotted Microline reactor...... with hydrochloric acid, allowing an ensuing determination via hydride generation. At different sample flow rates, i.e., 4.8, 6.4 and 8.8 ml/min, enrichment factors of 30, 40 and 46, respectively, were obtained at a sampling frequency of 33 samples/h. The detection limit (3s) was 0.005 µg/l at a sample flow rate...

  3. Land-use regression panel models of NO2 concentrations in Seoul, Korea

    Science.gov (United States)

    Kim, Youngkook; Guldmann, Jean-Michel

    2015-04-01

    Transportation and land-use activities are major air pollution contributors. Since their shares of emissions vary across space and time, so do air pollution concentrations. Despite these variations, panel data have rarely been used in land-use regression (LUR) modeling of air pollution. In addition, the complex interactions between traffic flows, land uses, and meteorological variables, have not been satisfactorily investigated in LUR models. The purpose of this research is to develop and estimate nitrogen dioxide (NO2) panel models based on the LUR framework with data for Seoul, Korea, accounting for the impacts of these variables, and their interactions with spatial and temporal dummy variables. The panel data vary over several scales: daily (24 h), seasonally (4), and spatially (34 intra-urban measurement locations). To enhance model explanatory power, wind direction and distance decay effects are accounted for. The results show that vehicle-kilometers-traveled (VKT) and solar radiation have statistically strong positive and negative impacts on NO2 concentrations across the four seasonal models. In addition, there are significant interactions with the dummy variables, pointing to VKT and solar radiation effects on NO2 concentrations that vary with time and intra-urban location. The results also show that residential, commercial, and industrial land uses, and wind speed, temperature, and humidity, all impact NO2 concentrations. The R2 vary between 0.95 and 0.98.

  4. Vital improvements to the retrieval of tropospheric NO2 columns from the Ozone Monitoring Instrument

    Science.gov (United States)

    Maasakkers, Joannes D.; Folkert Boersma, K.; Williams, Jason E.; van Geffen, Jos; Vinken, Geert C. M.; Sneep, Maarten; Hendrick, Francois; van Roozendael, Michel; Pepijn Veefkind, J.

    2013-04-01

    Nitrogen oxides (NOx = NO + NO2) play an important role in tropospheric chemistry, they catalyze the production of ozone (O3) and contribute to aerosol formation. NOx is linked to the oxidizing efficiency of the atmosphere since O3 plays an important role in the formation of OH. Satellite observations of NO2 are important for monitoring and studying concentrations of nitrogen oxides, but considerable uncertainties on the accuracy and robustness of the retrievals, and their fitness for model evaluation still persist. These uncertainties pertain to all aspects of the retrieval: (1) spectral fitting, (2) stratospheric background correction, and (3) air mass factor calculation. Here we present a number of relevant improvements to the tropospheric nitrogen dioxide column retrieval algorithm from OMI (DOMINO v3). We revisit the 405-465 nm spectral fitting window for the OMI NO2 slant column retrievals, and suggest adaptations to this window to improve agreement with (stratospheric) columns obtained from SCIAMACHY and GOME-2, as validated with independent FTIR NO2 columns observed from the ground at Jungfraujoch. Furthermore, stronger nudging of the stratospheric O3:HNO3 ratios in the TM5 chemistry transport model (used to estimate the stratospheric background NO2) with those observed by the ODIN instrument, enables us to improve stratospheric NO2 simulations with substantial benefits for the assimilation and stratospheric NO2 corrections in the retrieval. A third important innovation is the coupling of the Dutch OMI NO2 retrieval to the TM5 model with a global resolution of 1°×1°. As suggested previously by Boersma et al. [2007] and demonstrated by Heckel et al. [2011], the better resolved a priori profile shapes lead to a much better understanding of pollution gradients observed from space. In addition to the increased resolution, updated chemistry and emissions (improved soil and ship NOx emissions) in TM5 make the OMI retrieved tropospheric NO2 columns

  5. Validation of MIPAS-ENVISAT NO2 operational data

    Directory of Open Access Journals (Sweden)

    R. Ruhnke

    2007-06-01

    Full Text Available The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS instrument was launched aboard the environmental satellite ENVISAT into its sun-synchronous orbit on 1 March 2002. The short-lived species NO2 is one of the key target products of MIPAS that are operationally retrieved from limb emission spectra measured in the stratosphere and mesosphere. Within the MIPAS validation activities, a large number of independent observations from balloons, satellites and ground-based stations have been compared to European Space Agency (ESA version 4.61 operational NO2 data comprising the time period from July 2002 until March 2004 where MIPAS measured with full spectral resolution. Comparisons between MIPAS and balloon-borne observations carried out in 2002 and 2003 in the Arctic, at mid-latitudes, and in the tropics show a very good agreement below 40 km altitude with a mean deviation of roughly 3%, virtually without any significant bias. The comparison to ACE satellite observations exhibits only a small negative bias of MIPAS which appears not to be significant. The independent satellite instruments HALOE, SAGE II, and POAM III confirm in common for the spring-summer time period a negative bias of MIPAS in the Arctic and a positive bias in the Antarctic middle and upper stratosphere exceeding frequently the combined systematic error limits. In contrast to the ESA operational processor, the IMK/IAA retrieval code allows accurate inference of NO2 volume mixing ratios under consideration of all important non-LTE processes. Large differences between both retrieval results appear especially at higher altitudes, above about 50 to 55 km. These differences might be explained at least partly by non-LTE under polar winter conditions but not at mid-latitudes. Below this altitude region mean differences between both processors remain within 5% (during night and up to 10% (during day under undisturbed (September 2002 conditions and up to 40% under perturbed

  6. Pengakuan Biaya Riset dan Pengembangan : Tinjauan terhadap SFAS No. 2

    Directory of Open Access Journals (Sweden)

    Inon Listyorini

    2016-02-01

    Full Text Available SFAS No. 2 requires that research and development costs to be recognized as an expense in the period of issuance of such costs. Such treatment caused problems matching revenue with expenses can not be met, the concept of grouping resources as assets applied inconsistently and the trade off between the qualitative characteristics of relevance with reliability in the presentation of research and development costs. Capitalization of research and development costs can be done to overcome these problems, with the capitalization requirements made after the technical feasibility test.

  7. Ornithological Survey of the Proposed Geothermal Well Site No. 2

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey, Jack

    1990-08-16

    The U.S. Fish and Wildlife Service (USFWS 1983) and the State of Hawaii (DLNR 1986) have listed as endangered six forest bird species for the Island of Hawaii. Two of these birds, the O'u (Psittirostra psittacea) and the Hawaiian hawk (Buteo solitarius) may be present within the Geothermal resource sub-zone (Scott et al. 1986). Thus, their presence could impact future development within the resource area. This report presents the results of a bird survey conducted August 11 and 12, 1990 in the sub-zone in and around the proposed well site and pad for True/Mid Pacific Geothermal Well No.2.

  8. DWPF Melter No.2 Prototype Bus Bar Test Report

    International Nuclear Information System (INIS)

    Gordon, J.

    2003-01-01

    Characterization and performance testing of a prototype DWPF Melter No.2 Dome Heater Bus Bar are described. The prototype bus bar was designed to address the design features of the existing system which may have contributed to water leaks on Melter No.1. Performance testing of the prototype revealed significant improvement over the existing design in reduction of both bus bar and heater connection maximum temperature, while characterization revealed a few minor design and manufacturing flaws in the bar. The prototype is recommended as an improvement over the existing design. Recommendations are also made in the area of quality control to ensure that critical design requirements are met

  9. Where are the radioactive wastes in France? Brochure no 2

    International Nuclear Information System (INIS)

    2004-01-01

    This document is one of the 6 regional brochures which make the geographical inventory of radioactive wastes in France. For each region, a table lists the recorded sites and a regional map localizes those having a detailed descriptive file. These files mention the most important waste owners (medical, research, nuclear and military industries), the type of waste and the type of management. The polluted sites are also mentioned, even if they are already decontaminated. The volume no 2 concerns the Bretagne (Brittany), Pays de la Loire, Haute-Normandie, Basse-Normandie and Centre regions. (J.S.)

  10. NO2 Vertical Column Density at the Marambio Antarctic Station as Retrieved by DOAS

    Science.gov (United States)

    Raponi, Marcelo M.; Jiménez, Rodrigo; Tocho, Jorge O.; Quel, Eduardo J.

    2009-03-01

    A number of chemical species present in the stratosphere in very small concentrations (parts per billion and even smaller) contribute significantly to its chemical balance. One of the main stratospheric trace gases is nitrogen dioxide (NO2). This species acts as a restrictive agent for stratospheric ozone destruction (due to the chlorine monoxide), hence the importance of its study. We present a preliminary analysis of passive remote sensing measurements carry out at the Marambio Argentinean Antarctic Base (64.233° S; 56.616° W; 197 m amsl) during the months of January—February of 2008. The spectroscopy system consists of an optical fiber (400 μm core diameter and 6 m of longitude) and a portable spectral analyzer (spectrometer HR4000, Ocean Optics). The device analyzes diffuse solar spectral irradiance in the UV-visible range (290-650 nm), collected and transferred by a zenith-pointing optical fiber. The NO2 vertical column density (VCD) is derived from the radiance spectra using the DOAS (Differential Optical Absorption Spectroscopy) technique. The system and technique allow for simultaneous measurements of different species of interest on a variety of meteorological conditions. The vertical columns obtained are compared with co-located measurements performed with EVA, a visible absorption spectrometer operated by the Instituto Nacional de Técnica Aeroespacial (INTA), Spain.

  11. Estimates of Free-tropospheric NO2 Abundance from the Aura Ozone Monitoring Instrument (OMI) Using Cloud Slicing Technique

    Science.gov (United States)

    Choi, S.; Joiner, J.; Krotkov, N. A.; Choi, Y.; Duncan, B. N.; Celarier, E. A.; Bucsela, E. J.; Vasilkov, A. P.; Strahan, S. E.; Veefkind, J. P.; Cohen, R. C.; Weinheimer, A. J.; Pickering, K. E.

    2013-12-01

    Total column measurements of NO2 from space-based sensors are of interest to the atmospheric chemistry and air quality communities; the relatively short lifetime of near-surface NO2 produces satellite-observed hot-spots near pollution sources including power plants and urban areas. However, estimates of NO2 concentrations in the free-troposphere, where lifetimes are longer and the radiative impact through ozone formation is larger, are severely lacking. Such information is critical to evaluate chemistry-climate and air quality models that are used for prediction of the evolution of tropospheric ozone and its impact of climate and air quality. Here, we retrieve free-tropospheric NO2 volume mixing ratio (VMR) using the cloud slicing technique. We use cloud optical centroid pressures (OCPs) as well as collocated above-cloud vertical NO2 columns (defined as the NO2 column from top of the atmosphere to the cloud OCP) from the Ozone Monitoring Instrument (OMI). The above-cloud NO2 vertical columns used in our study are retrieved independent of a priori NO2 profile information. In the cloud-slicing approach, the slope of the above-cloud NO2 column versus the cloud optical centroid pressure is proportional to the NO2 volume mixing ratio (VMR) for a given pressure (altitude) range. We retrieve NO2 volume mixing ratios and compare the obtained NO2 VMRs with in-situ aircraft profiles measured during the NASA Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaign in 2006. The agreement is good when proper data screening is applied. In addition, the OMI cloud slicing reports a high NO2 VMR where the aircraft reported lightning NOx during the Deep Convection Clouds and Chemistry (DC3) campaign in 2012. We also provide a global seasonal climatology of free-tropospheric NO2 VMR in cloudy conditions. Enhanced NO2 in free troposphere commonly appears near polluted urban locations where NO2 produced in the boundary layer may be transported vertically out of the

  12. Nuclear materials 1993 annual report. Volume 8, No. 2

    International Nuclear Information System (INIS)

    1995-05-01

    This annual report of the US Nuclear Regulatory Commission's Office for Analysis and Evaluation of Operational Data (AEOD) describes activities conducted during 1993. The report is published in two parts. NUREG-1272, Vol. 8, No. 1, covers power reactors and presents an overview of the operating experience of the nuclear power industry from the NRC perspective, including comments about the trends of some key performance measures. The report also includes the principal findings and issues identified in AEOD studies over the past year and summarizes information from such sources as licensee event reports, diagnostic evaluations, and reports to the NRC's Operations Center. NUREG-1272, Vol. 8, No. 2, covers nuclear materials and presents a review of the events and concerns during 1993 associated with the use of licensed material in nonreactor applications, such as personnel overexposures and medical misadministrations. Note that the subtitle of No. 2 has been changed from ''Nonreactors'' to ''Nuclear Materials.'' Both reports also contain a discussion of the Incident Investigation Team program and summarize both the Incident Investigation Team and Augmented Inspection Team reports. Each volume contains a list of the AEOD reports issued from 1980 through 1993

  13. Nuclear materials 1993 annual report. Volume 8, No. 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    This annual report of the US Nuclear Regulatory Commission`s Office for Analysis and Evaluation of Operational Data (AEOD) describes activities conducted during 1993. The report is published in two parts. NUREG-1272, Vol. 8, No. 1, covers power reactors and presents an overview of the operating experience of the nuclear power industry from the NRC perspective, including comments about the trends of some key performance measures. The report also includes the principal findings and issues identified in AEOD studies over the past year and summarizes information from such sources as licensee event reports, diagnostic evaluations, and reports to the NRC`s Operations Center. NUREG-1272, Vol. 8, No. 2, covers nuclear materials and presents a review of the events and concerns during 1993 associated with the use of licensed material in nonreactor applications, such as personnel overexposures and medical misadministrations. Note that the subtitle of No. 2 has been changed from ``Nonreactors`` to ``Nuclear Materials.`` Both reports also contain a discussion of the Incident Investigation Team program and summarize both the Incident Investigation Team and Augmented Inspection Team reports. Each volume contains a list of the AEOD reports issued from 1980 through 1993.

  14. Actinometric measurements of NO2 photolysis frequencies in the atmosphere simulation chamber SAPHIR

    Directory of Open Access Journals (Sweden)

    B. Bohn

    2005-01-01

    Full Text Available The simulation chamber SAPHIR at Forschungszentrum Jülich has UV permeable teflon walls facilitating atmospheric photochemistry studies under the influence of natural sunlight. Because the internal radiation field is strongly affected by construction elements, we use external, radiometric measurements of spectral actinic flux and a model to calculate mean photolysis frequencies for the chamber volume Bohn04B. In this work we determine NO2 photolysis frequencies j(NO2 within SAPHIR using chemical actinometry by injecting NO2 and observing the chemical composition during illumination under various external conditions. In addition to a photo-stationary approach, a time-dependent method was developed to analyse the data. These measurements had two purposes. Firstly, to check the model predictions with respect to diurnal and seasonal variations in the presence of direct sunlight and secondly to obtain an absolute calibration factor for the combined radiometry-model approach. We obtain a linear correlation between calculated and actinometric j(NO2. A calibration factor of 1.34±0.10 is determined, independent of conditions in good approximation. This factor is in line with expectations and can be rationalised by internal reflections within the chamber. Taking into account the uncertainty of the actinometric j(NO2, an accuracy of 13% is estimated for the determination of j(NO2 in SAPHIR. In separate dark experiments a rate constant of (1.93±0.12x10-14 cm3 s-1 was determined for the NO+O3 reaction at 298K using analytical and numerical methods of data analysis.

  15. Upgrade of the DAUMOD atmospheric dispersion model to estimate urban background NO2 concentrations

    Science.gov (United States)

    Pineda Rojas, Andrea L.; Venegas, Laura E.

    2013-02-01

    Ambient concentrations of nitrogen dioxide (NO2) resulting from the emissions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) in an urban area may cause adverse impacts on the human health and the natural environment if they exceed the air quality standards. The evaluation of NO2 can be achieved through the application of air quality models including photochemical reactions. DAUMOD is a simple urban scale atmospheric dispersion model which was originally developed to estimate urban background concentrations of inert species. In order to allow the estimation of NO2 concentrations in an urban atmosphere, the DAUMOD model has been recently coupled to the Generic Reaction Set (GRS), a simplified photochemical scheme. This work presents the development of the DAUMOD-GRS model and its first application in the city of Buenos Aires considering high resolution area source NOx and VOC emissions recently obtained for the area. Estimated hourly NO2 concentrations are compared with the observations from a campaign carried out at a green open area within the city in winter 2001. Results show a good model performance, with NMSE = 0.49, FA2 = 0.676 and FB = - 0.097. DAUMOD-GRS is applied to obtain the spatial distribution of annual NO2 concentrations in the city. The maximum value is 36 ppb, indicating that annual NO2 concentrations in Buenos Aires are below the Air Quality Standard (53 ppb). In addition, hourly ozone concentrations estimated by DAUMOD-GRS are compared with observed values, giving NMSE = 0.38, FA2 = 0.684 and FB = - 0.225.

  16. Winter Distribution of On-road NO2 Concentration in Hong Kong

    Science.gov (United States)

    Zhu, Y.; Chan, K. L.; Boll, J.; Schütt, A. M. N.; Lipkowitsch, I.; Wenig, M.

    2017-12-01

    In this study, we investigated the spatial distribution of on road NO2 concentration using Cavity-Enhanced Differential Optical Absorption Spectroscopy (DOAS). We performed two measurement campaigns in winter 2010 and 2017. Air pollution is a severe problem for many big cities, especially in Asia. Traffic emission is the primary source of urban pollutants. As Hong Kong is one of the most densely populated cities in the world, many inhabitants are exposed to accumulated pollutants in street canyons. Our mobile measurements were performed for a week in December, 2010 and March, 2017. Additionally, long term air pollution data measured by a long-path DOAS (LP-DOAS) and the Environment Protection Department (EPD) air quality monitoring network were used to investigate the long term trend and seasonal variations of atmospheric NO2 in Hong Kong.The experiment setup and preliminary results of mobile measurements are presented. The measurements were performed along a fixed route which covers most of the urban area. We assembled a NO2 concentration map 2 to 3 times per day in order to cover both morning and evening rush hours. In order to construct a consistent map, we use coinciding LP-DOAS NO2 data to correct for the diurnal cycle. Furthermore, the spatial and temporal distribution of NO2 changes with the day of the week. Traffic load is highly dependent on human activities which typically fall into a 7 days cycle. Therefore, we have analyzed the weekly pattern of on road NO2 distribution to see the differences between anthropogenic emissions during weekdays and weekend.

  17. Oak Ridge National Laboratory review: Volume 20, No. 2, 1987

    Energy Technology Data Exchange (ETDEWEB)

    Krause, C.; Zucker, A.; Corrill, L. (eds.)

    1987-01-01

    After a brief statement on the 1986 state of the laboratory, science highlights in collaborative research are presented: an attempt to recreate the first moments of the Big Bang, surface modification techniques in electronics, assessing home radon levels in five states, managing international integrated forest study, US-Japan joint breeder reprocessing project, optical components for SDI, evaluating the Chernobyl reactor accident, fusion superconducting magnet and fueling, scanning tunneling microscope, laser-processed solar cells, explosive trace detector, parallel computer processing algorithms, risk of fertilized egg to teratogens, trees for biomass energy, toxic waste leaching test, corn fermentation, and electricity distribution automation at Athens, TN. Milestones, other programs, the HFIR situation, book publications, and news are finally given. (DLC)

  18. Oak Ridge National Laboratory review: Volume 20, No. 2, 1987

    International Nuclear Information System (INIS)

    Krause, C.; Zucker, A.; Corrill, L.

    1987-01-01

    After a brief statement on the 1986 state of the laboratory, science highlights in collaborative research are presented: an attempt to recreate the first moments of the Big Bang, surface modification techniques in electronics, assessing home radon levels in five states, managing international integrated forest study, US-Japan joint breeder reprocessing project, optical components for SDI, evaluating the Chernobyl reactor accident, fusion superconducting magnet and fueling, scanning tunneling microscope, laser-processed solar cells, explosive trace detector, parallel computer processing algorithms, risk of fertilized egg to teratogens, trees for biomass energy, toxic waste leaching test, corn fermentation, and electricity distribution automation at Athens, TN. Milestones, other programs, the HFIR situation, book publications, and news are finally given

  19. Where are the radioactive wastes in France? Brochure no 2; Ou sont les dechets radioactifs en France? Brochure no 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This document is one of the 6 regional brochures which make the geographical inventory of radioactive wastes in France. For each region, a table lists the recorded sites and a regional map localizes those having a detailed descriptive file. These files mention the most important waste owners (medical, research, nuclear and military industries), the type of waste and the type of management. The polluted sites are also mentioned, even if they are already decontaminated. The volume no 2 concerns the Bretagne (Brittany), Pays de la Loire, Haute-Normandie, Basse-Normandie and Centre regions. (J.S.)

  20. Diagnosing MOV problems using comparative trace analysis

    International Nuclear Information System (INIS)

    Leon, R.L.

    1992-01-01

    The paper presents the concept of comparative trace analysis and shows it to be very effective in diagnosing motor operated valve (MOV) problems. Comparative trace analysis is simply the process of interpreting simultaneously gathered traces, each presenting a different perspective on the same series of events. The opening and closing of a motor operated valve is such a series of events. The simultaneous traces are obtained using Liberty Technologies' Valve Operation Test and Evaluation System (VOTES)reg-sign. The traces include stem thrust, motor current, motor power factor, motor power, switch actuations, vibration in three different frequency bands, spring pack displacement, and spring pack force. Spare and auxiliary channels enable additional key parameters to be measured, such as differential pressure and stem displacement. Though not specifically illustrated in this paper, the VOTES system also provides for FFT analysis on all traces except switches

  1. LMFBR Blanket Physics Project progress report No. 2

    International Nuclear Information System (INIS)

    Forbes, I.A.; Driscoll, M.J.; Rasmussen, N.C.; Lanning, D.D.; Kaplan, I.

    1971-01-01

    This is the second annual report of an experimental program for the investigation of the neutronics of benchmark mock-ups of LMFBR blankets. Work was devoted primarily to measurements on Blanket Mock-Up No. 2, a simulation of a typical large LMFBR radial blanket and its steel reflector. Activation traverses and neutron spectra were measured in the blanket; calculations of activities and spectra were made for comparison with the measured data. The heterogeneous self-shielding effect for 238 U capture was found to be the most important factor affecting the comparison. Optimization and economic studies were made which indicate that the use of a high-albedo reflector material such as BeO or graphite may improve blanket neutronics and economics

  2. Production of electronically excited NO via DEA to NO2

    Science.gov (United States)

    Gope, Krishnendu; Tadsare, Vishvesh; Prabhudesai, Vaibhav S.; Krishnakumar, E.

    2017-12-01

    Dissociative electron attachment (DEA) to NO2 in the 7-11 eV range is studied using velocity slice imaging technique. Two distinct channels are observed in the DEA corresponding to O- + NO(A 2Σ+) and O- + NO(C 2Π and/or D 2Σ+). While NO(A 2Σ+) is found to be formed only in very high vibrational levels, NO(C 2Π and/or D 2Σ+) is found to be formed with vibrational distribution starting from v = 0. From the angular distribution of the O- ions leading to the NO(C 2Π and/or D 2Σ+) channel, we obtain the symmetry of the negative ion resonance to be dominantly B1 with small contribution from B2. Contribution to the Topical Issue: "Low Energy Positron and Electron Interactions", edited by James Sullivan, Ron White, Michael Bromley, Ilya Fabrikant, and David Cassidy.

  3. Selective Detection of NO2 Using Cr-Doped CuO Nanorods

    Science.gov (United States)

    Kim, Kang-Min; Jeong, Hyun-Mook; Kim, Hae-Ryong; Choi, Kwon-Il; Kim, Hyo-Joong; Lee, Jong-Heun

    2012-01-01

    CuO nanosheets, Cr-doped CuO nanosheets, and Cr-doped CuO nanorods were prepared by heating a slurry containing Cu-hydroxide/Cr-hydroxide. Their responses to 100 ppm NO2, C2H5OH, NH3, trimethylamine, C3H8, and CO were measured. For 2.2 at% Cr-doped CuO nanorods, the response (Ra/Rg, Ra: resistance in air, Rg: resistance in gas) to 100 ppm NO2 was 134.2 at 250 °C, which was significantly higher than that of pure CuO nano-sheets (Ra/Rg = 7.5) and 0.76 at% Cr-doped CuO nanosheets (Ra/Rg = 19.9). In addition, the sensitivity for NO2 was also markedly enhanced by Cr doping. Highly sensitive and selective detection of NO2 in 2.2 at% Cr-doped CuO nanorods is explained in relation to Cr-doping induced changes in donor density, morphology, and catalytic effects. PMID:22969384

  4. Decline in tropospheric NO2 and the effects of the 2008-09 economic crisis observed by OMI over Europe

    Science.gov (United States)

    Castellanos, P.; Boersma, F. F.

    2011-12-01

    We present a trend analysis of tropospheric NO2 for the time period of 2004-2010. Necessary for monitoring pollution abatement strategies, NO2 trends analyses are often based on surface networks, which suffer from high NO2 biases and spatial representativity issues inherent to the standard monitoring method (thermal reduction of NO2 followed by reaction with ozone and chemiluminescence). Space based NO2 trends are unbiased and self-consistent, but over Europe they have not been as obvious as those observed over North America and East Asia. In this work we exploit the daily NO2 column observations from the Ozone Monitoring Instrument (OMI) in order to isolate long-term (timescales greater than one year) variability in NO2 over Europe without imposing a parametric fit to the data. In general, we find between 2005 and 2008, 1-5% per year declines in NO2 concentration in many polluted regions (e.g. Germany, Netherlands, Belgium, Italy, Spain), but also 1-5% per year increases over the English Channel and the southern North Sea (a major shipping channel), as well as the United Kingdom, northern France and Eastern Europe. In 2009, NO2 almost exclusively decreased over Europe at a rate of 5-10% per year, coinciding with the abrupt decrease in industrial production and construction prompted by the global economic crisis. By 2010, in many areas the NO2 rate of change returned to pre-2009 levels suggesting economic recovery. We employ a simple fitting model to separate the forcing by meteorological variability, which can influence apparent NO2 trends, from that of NOx emissions. We calculate 1-3% per year NOx emissions reduction rates over most of Europe and an additional 15-30% per year decrease in NOx emissions during the economic crisis time period.

  5. Hydrocarbons identified in extracts from estuarine water accommodated no. 2 fuel oil by gas chromatography-mass spectrometry

    Science.gov (United States)

    Lewis, B. W.; Walker, A. L.; Bieri, R. H.

    1974-01-01

    Results are presented on a computerized gas chromatograph-mass spectrometer analysis of methylene chloride and n-heptane extracts of a No. 2 fuel oil accommodated estuarine water sample. The analytical method is briefly described, and the limitations on the identifications are categorized. Some attempt was made to determine major and trace constituents in the water accommodate. Altogether 66 hydrocarbon compounds were identified specifically, and 75 compounds were partially identified. Seven compounds could be recognized as major constituents of the water accommodated oil and ten were present only as traces. The aromatic compounds found were alkyl benzenes, naphthalene, tetralin, indane, biphenyl, fluorene, anthracene, and some of their alkyl substituted isomers in the range of carbon numbers C7 to C15. Four n-alkanes, C10 to C13, were found along with four other assorted hydrocarbons.

  6. Influence of nitrogen oxides NO and NO2 on singlet delta oxygen production in pulsed discharge

    International Nuclear Information System (INIS)

    Ionin, A A; Klimachev, Yu M; Kozlov, A Yu; Kotkov, A A; Rulev, O A; Seleznev, L V; Sinitsyn, D V; Vagin, N P; Yuryshev, N N; Kochetov, I V; Napartovich, A P

    2009-01-01

    The influence of nitrogen oxides NO and NO 2 on the specific input energy (SIE) and the time behaviour of singlet delta oxygen (SDO) luminescence excited by a pulsed e-beam sustained discharge in oxygen were experimentally and theoretically studied. NO and NO 2 addition into oxygen results in a small increase and decrease in the SIE, respectively, the latter being connected with a large energy of electron affinity to NO 2 . The addition of 0.1-0.3% nitrogen oxides was experimentally and theoretically demonstrated to result in a notable enhancement of the SDO lifetime, which is related to a decrease in the atomic oxygen concentration in afterglow. It was experimentally demonstrated that to get a high SDO concentration at the gas pressure 30-60 Torr for a time interval of less than ∼0.5 s one needs to add not less than 0.2% nitrogen oxides into oxygen. The temperature dependence of the relaxation constant for SDO quenching by unexcited oxygen was estimated by using experimental data on the time behaviour of SDO luminescence.

  7. Catalytic oxidation of NO to NO2 on activated carbon

    International Nuclear Information System (INIS)

    Zhancheng Guo; Yusheng Xie

    2001-01-01

    Catalytic oxidation of NO to NO 2 over activated carbons PAN-ACF, pitch-ACF and coconut-AC at room temperature (30 o C) were studied to develop a method based on oxidative removal of NO from flue gases. For a dry gas, under the conditions of a gas space flow rate 1500 h -1 in the presence of oxygen of 2-20% in volume concentration, the activated coconut carbon with a surface area 1200 m 2 /g converted about 81-94% of NO with increasing oxygen concentration, the pitch based activated carbon fiber with a surface area 1000 m 2 /g about 44-75%, and the polyacrylonitrile-based activated carbon fiber with a surface area 1810 m 2 /g about 25-68%. The order of activity of the activated carbons was PAN-ACF c P NO P O2 β (F/W), where β is 0.042, 0.16, 0.31 for the coconut-AC, the pitch-ACF and the PAN-ACF respectively, and k c is 0.94 at 30 o C. (author)

  8. Evaluation of failure of high lift diesel No. 2

    International Nuclear Information System (INIS)

    Loundagin, R.L.

    1976-01-01

    At 6:30 a.m., September 21, 1976, the No. 2 Emergency High Lift Pump Diesel Engine was remotely started from the N Reactor Control Room to provide water for flushing the N Reactor Emergency Cooling System piping. The engine is a General Motors Diesel Engine Model 16-278A, 2 cycle V type, 16 cylinder, developing 1600 horsepower at 750 revolutions per minute. During the flush, water was observed to be overflowing the engine's jacket cooling water expansion tank. The N Reactor Control Room was notified, and the engine was shut down after having run for approximately 15 minutes. Examination of the engine found the No. 5 cylinder liner had ruptured, causing air to be forced into the cooling system. When the engine was stopped, cooling water was admitted to the engine air box and crankcase. All 16 cylinder heads were removed and the cylinder liners were examined using liquid penetrant to detect cracks. A cracked cylinder liner was found in cylinder No. 6, and the cylinder head of cylinder No. 1 was also found to be cracked. An adherent scale and light pitting were observed on the heads of the pistons in cylinders No. 1, 5, and 6, but not in any other cylinders. All damaged parts were replaced, and the engine was reassembled, tested, and declared serviceable

  9. The rate coefficient for the reaction NO2 + NO3 yielding NO + NO2 + O2 from 273 to 313 K

    Science.gov (United States)

    Cantrell, Chris A.; Shetter, Richard E.; Mcdaniel, Anthony H.; Calvert, Jack G.

    1990-01-01

    The ratio of rate constants for the reaction NO3 + NO yielding 2 NO2 (k3) and the reaction NO2 + NO3 yielding NO + NO2 + O2 (k4) were determined by measuring of NO and NO2 concentrations of NO and NO2 in an N2O5/NO2/N2 mixture over the temperature range 273-313 K. The measured ratio was found to be expressed by the equation k3/k4 = 387 exp(-1375/T). The results are consistent with those of Hammer et al. (1986).

  10. Nitrogen dioxide observations from the Geostationary Trace ...

    Science.gov (United States)

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument is a test bed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA Falcon aircraft in its first intensive field measurement campaign during the Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) Earth Venture Mission over Houston, Texas, in September 2013. Measurements of backscattered solar radiation between 420 and 465 nm collected on 4 days during the campaign are used to determine slant column amounts of NO2 at 250 m  ×  250 m spatial resolution with a fitting precision of 2.2 × 1015 moleculescm−2. These slant columns are converted to tropospheric NO2 vertical columns using a radiative transfer model and trace gas profiles from the Community Multiscale Air Quality (CMAQ) model. Total column NO2 from GeoTASO is well correlated with ground-based Pandora observations (r = 0.90 on the most polluted and cloud-free day of measurements and r = 0.74 overall), with GeoTASO NO2 slightly higher for the most polluted observations. Surface NO2 mixing ratios inferred from GeoTASO using the CMAQ model show good correlation with NO2 measured in situ at the surface during the campaign (r = 0.85). NO2 slant columns from GeoTASO also agree well with prelim

  11. Retrieval of tropospheric NO2 using the MAX-DOAS method combined with relative intensity measurements for aerosol correction

    Directory of Open Access Journals (Sweden)

    P. F. Levelt

    2010-10-01

    Full Text Available Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS is a technique to measure trace gas amounts in the lower troposphere from ground-based scattered sunlight observations. MAX-DOAS observations are especially suitable for validation of tropospheric trace gas observations from satellite, since they have a representative range of several kilometers, both in the horizontal and in the vertical dimension. A two-step retrieval scheme is presented here, to derive aerosol corrected tropospheric NO2 columns from MAX-DOAS observations. In a first step, boundary layer aerosols, characterized in terms of aerosol optical thickness (AOT, are estimated from relative intensity observations, which are defined as the ratio of the sky radiance at elevation α and the sky radiance in the zenith. Relative intensity measurements have the advantage of a strong dependence on boundary layer AOT and almost no dependence on boundary layer height. In a second step, tropospheric NO2 columns are derived from differential slant columns, based on AOT-dependent air mass factors. This two-step retrieval scheme was applied to cloud free periods in a twelve month data set of observations in De Bilt, The Netherlands. In a comparison with AERONET (Cabauw site a mean difference in AOT (AERONET minus MAX-DOAS of −0.01±0.08 was found, and a correlation of 0.85. Tropospheric-NO2 columns were compared with OMI-satellite tropospheric NO2. For ground-based observations restricted to uncertainties below 10%, no significant difference was found, and a correlation of 0.88.

  12. Journal for Language Teaching - Vol 43, No 2 (2009)

    African Journals Online (AJOL)

    Monitoring the standard of a Grade 12 English First Additional Language Reading, Comprehension, Summary and Grammar Paper · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. W Coetzee, R Johl. http://dx.doi.org/10.4314/jlt.v43i2.56967 ...

  13. ORiON - Vol 33, No 2 (2017)

    African Journals Online (AJOL)

    A retrial queueing-inventory system with J-additional options for service and nite source · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. VSS Yadavalli, K Jeganathan, T Venkatesan, S Padmasekaran, S Jehoashan Kingsly, 105-135 ...

  14. Nigerian Journal of Technological Development - Vol 13, No 2 (2016)

    African Journals Online (AJOL)

    Influence of scanning speed on the microhardness property of additive manufactured titanium alloy · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. R.M. Mahamood, 83-87. http://dx.doi.org/10.4314/njtd.v13i2.6 ...

  15. Nigerian Food Journal - Vol 30, No 2 (2012)

    African Journals Online (AJOL)

    JO Arawande, OY Ogunyemi. http://dx.doi.org/10.1016/S0189-7241(15)30027-8 ... Effect of Soy Flour and Maize Flour Addition on Phase Separation in Moi- Moi from Soaked Cowpea (Vigna unguiculata) and Cowpea Flour from Different Cowpea Varieties · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT ...

  16. Trace Minerals and Livestock: Not Too Much Not Too Little

    OpenAIRE

    L?pez-Alonso, Marta

    2012-01-01

    The new approaches of the animal production systems make managing the mineral nutrition a challenge. Versus the excessive, trace mineral supply in intensively managed livestock, well above the physiological requirements, is the no trace mineral supplementation of organic systems, which become highly dependent on trace minerals in the soil. Nowadays, in addition to the animal health perspective, trace mineral nutrition must be environment friendly and allow getting mineral-enriched animal prod...

  17. The Trace of Superusers

    DEFF Research Database (Denmark)

    Samson, Kristine; Abasolo, José

    2013-01-01

    of people’s everyday life.However, traces of culture, the routines and every day habits of immigrant culture can both emerge through informal colonization in the every day and be intentionally designed. By juxtaposing immigrant spatial traces in Santiago Centro with the intentionally designed traces......The city and its public spaces can be seen as a fragmented whole carrying meanings and traces of culture, use and politics with it. Whereas architects impose new stories and meanings on the urban fabric, the city itself is layered and assembled, a collective of social flows and routines a result...... of immigrant culture at Superkilen, Nørrebro in Copenhagen, this article seeks to discuss how traces influence public space, and how various ideologies and even politics are interwoven into the urban fabric by means of urban traces....

  18. Population Intervention Models to Estimate Ambient NO2 Health Effects in Children with Asthma

    Science.gov (United States)

    Snowden, Jonathan M.; Mortimer, Kathleen M.; Dufour, Mi-Suk Kang; Tager, Ira B.

    2015-01-01

    Health effects of ambient air pollution are most frequently expressed in individual studies as responses to a standardized unit of air pollution changes (e.g., an interquartile interval), which is thought to enable comparison of findings across studies. However, this approach does not necessarily convey health effects in terms of a real-world air pollution scenario. In the present study, we employ population intervention modeling to estimate the effect of an air pollution intervention that makes explicit reference to the observed exposure data and is identifiable in those data. We calculate the association between ambient summertime NO2 and forced expiratory flow between 25% and 75% of forced vital capacity (FEF25–75) in a cohort of children with asthma in Fresno, California. We scale the effect size to reflect NO2 abatement on a majority of summer days. The effect estimates were small, imprecise, and consistently indicated improved pulmonary function with decreased NO2. The effects ranged from −0.8% of mean FEF25–75 (95% Confidence Interval: −3.4 , 1.7) to −3.3% (95% CI: −7.5, 0.9). We conclude by discussing the nature and feasibility of the exposure change analyzed here given the observed air pollution profile, and we propose additional applications of the population intervention model in environmental epidemiology. PMID:25182844

  19. Preparation of nanostructured PbS thin films as sensing element for NO2 gas

    International Nuclear Information System (INIS)

    Kaci, S.; Keffous, A.; Hakoum, S.; Trari, M.; Mansri, O.; Menari, H.

    2014-01-01

    In this work, we demonstrate that semiconducting films of A IV B VI compounds, in particular, of nanostructured lead sulfide (PbS) which prepared by chemical bath deposition (CBD), can be used as a sensing element for nitrogen dioxide (NO 2 ) gas. The CBD method is versatile, simple in implementation and gives homogeneous semiconductor structures. We have prepared PbS nanocrystalline thin film at different reaction baths and temperatures. In the course of deposition, variable amounts of additives, such as organic substances among them, were introduced into the baths. The energy dispersive analysis (EDX) confirms the chemical composition of PbS films. A current–voltage (I–V) characterization of Pd/nc-PbS/a-SiC:H pSi(100)/Al Schottky diode structures were studied in the presence of NO 2 gas. The gas sensing behavior showed that the synthesized PbS nanocrystalline thin films were influenced by NO 2 gas at room temperature. The results can be used for developing an experimental sensing element based on chemically deposited nanostructured PbS films which can be applicable in gas sensors.

  20. A 3D NO2 DOAS System to Capture Urban Concentrations

    Science.gov (United States)

    Wenig, M.; Chan, L.; Zhu, Y.; Schütt, A. M. N.; Kuhlmann, G.; Brunner, D.

    2016-12-01

    The Munich 3D DOAS measuring system combines four different types of DOAS measurement techniques and is installed on the roof of the building of the LMU Meteorological Institute at the center of Munich. In order to get a complete picture of the NO2 distribution we utilize a sensor fusion concept consisting of three longpath-DOAS instruments (LP-DOAS) scanning retroreflectors in different directions and distances, a multi-axis DOAS instrument (MAX-DOAS) performing elevation scans in different azimuth directions which is also capable to look directly into the sun allowing direct sun DOAS measurements, and a mobile cavity-enhanced DOAS instruments (CE-DOAS) capturing the citywide street level NO2 concentrations.The map from the mobile CE-DOAS is corrected for diurnal variations using the LP-DOAS data and a daily cycle analysis to get a consistent NO2 map. The LP-DOAS data averages over several kilometers and uses different measurement paths to capture the horizontal variations at roof top level. This data set will also be used to constrain the vertical profile shapes retrieved from the MAX-DOAS inversion. Constraining ground concentrations using the LP-DOAS and the total columns from the direct sun DOAS measurements allows us to retrieve additional profile parameters characterizing a radial component of fitted profiles which then leads to estimated 3D distributions putting together different azimuth scan results.The resulting data set is very valuable for satellite validation (e.g. OMI NO2) since we cover an area similar to an OMI ground pixel and provide the vertical profile to eliminate the biggest error source for the AMF calculation for the retrieval algorithm. We are also comparing our results to local measurement stations.

  1. Global NOx emission estimates derived from an assimilation of OMI tropospheric NO2 columns

    Directory of Open Access Journals (Sweden)

    K. Sudo

    2012-03-01

    Full Text Available A data assimilation system has been developed to estimate global nitrogen oxides (NOx emissions using OMI tropospheric NO2 columns (DOMINO product and a global chemical transport model (CTM, the Chemical Atmospheric GCM for Study of Atmospheric Environment and Radiative Forcing (CHASER. The data assimilation system, based on an ensemble Kalman filter approach, was applied to optimize daily NOx emissions with a horizontal resolution of 2.8° during the years 2005 and 2006. The background error covariance estimated from the ensemble CTM forecasts explicitly represents non-direct relationships between the emissions and tropospheric columns caused by atmospheric transport and chemical processes. In comparison to the a priori emissions based on bottom-up inventories, the optimized emissions were higher over eastern China, the eastern United States, southern Africa, and central-western Europe, suggesting that the anthropogenic emissions are mostly underestimated in the inventories. In addition, the seasonality of the estimated emissions differed from that of the a priori emission over several biomass burning regions, with a large increase over Southeast Asia in April and over South America in October. The data assimilation results were validated against independent data: SCIAMACHY tropospheric NO2 columns and vertical NO2 profiles obtained from aircraft and lidar measurements. The emission correction greatly improved the agreement between the simulated and observed NO2 fields; this implies that the data assimilation system efficiently derives NOx emissions from concentration observations. We also demonstrated that biases in the satellite retrieval and model settings used in the data assimilation largely affect the magnitude of estimated emissions. These dependences should be carefully considered for better understanding NOx sources from top-down approaches.

  2. Long-Term Changes of Tropospheric Trace Gases over Pakistan Derived From Multiple Satellite Instruments

    Science.gov (United States)

    Zeb, Naila; Fahim Khokhar, Muhammad; Murtaza, Rabbia; Noreen, Asma; Khalid, Tameem

    2016-07-01

    Air pollution is the expected key environmental issue of Pakistan in coming years due to its ongoing rapid economic growth and this trend suggests only worst air quality over time. In 2014, World bank reported the Pakistan's urban air quality among the most severe in the world and intimated the government to make improvement in air quality as a priority policy agenda. In addition it is recommended to strengthen the institutional and technical capacity of organizations responsible for air quality management. Therefore, the study is designed to put efforts in highlighting air quality issues. The study will provide first database for tropospheric trace gases over Pakistan. The study aims to analyse tropospheric concentrations of CO, TOC, NO2 and HCHO over Pakistan using multisensory data from January 2005 to January 2014. Spatio-temporal and seasonal variability of tropospheric trace gases is observed over the decade to explore long term trend. Hotspots are identified to see variation of species with latitude and to highlight possible sources of trace gases over the Pakistan. High concentrations of trace gases are mainly observed over the Punjab region, which may be attributed to its metropolitan importance. It is the major agricultural, industrialized and urbanized (nearly 60% of the Pakistan's population) sector of the country. Overall significant decreasing trend of CO is identified by MOPITT with relative change of 12.4%. Tropospheric ozone column (TOC) showed insignificant increasing trend with temporal increase of 10.4% whereas NO2 exhibited a significant temporal increase of about 28%. For formaldehyde (HCHO), an increase of about 3.8% is calculated for SCIAMACHY data. Well defined seasonal cycles for these trace gases are observed over the whole study period. CO concentrations showed peak in winter months (November/December/January/February) and dip in the months of Summer/Monsoon (June/July/August). In spite of CO, TCO increases gradually in March and peaks

  3. Effect of relative humidity on O3 and NO2 oxidation of SO2 on α-Al2O3 particles

    Science.gov (United States)

    Liu, Wenjun; He, Xiang; Pang, Shufeng; Zhang, Yunhong

    2017-10-01

    Heterogeneous reactions of SO2/O3 and SO2/NO2 with α-Al2O3 particles at different RHs were investigated using a gas-flow system combined with microscopic Fourier transform infrared (micro-FTIR) spectrometer. The results show that the trace gas O3 or NO2 leads to rapid conversion of SO2 to sulfate on the surface of α-Al2O3 particles in initial stage and then conversion rate decreases in the following stages. The rate of sulfate formation and uptake coefficient (γ) for SO2 in the two systems as a function of relative humidity (RH) are determined for the first time, which are all strongly enhanced more than seven-fold as the RH increase from 15% to 95% in initial stage for SO2/O3 and SO2/NO2. Moreover, the γ in the system of SO2/O3 on α-Al2O3 particles is more than 3-fold than that of SO2/NO2 for the similar RH condition. Our results may be broadly applicable to understand the effects of RH and trace gases (e.g., O3, NO2) for the converting SO2 into sulfate on the mineral dust, which supply basic data for atmospheric chemistry modeling studies.

  4. Soils Newsletter, Vol. 36, No. 2, January 2014

    International Nuclear Information System (INIS)

    2014-01-01

    The end of 2013 is fast approaching. The challenges and opportunities for the SWMCN Subprogramme are exciting, with the ever greater focus and awareness of policy makers and farming communities around the world on the management of land and agricultural water resources for sustainable agriculture. In addition, there is mounting pressure on the agricultural sector to reduce greenhouse gas (GHG) emissions. Development of land-water management tools and techniques is increasingly required by cropping and livestock farmers to improve soil and water quality, reduce soil erosion-land degradation, minimize GHG from farm lands, improve soil fertility and produce more food per drop in both rainfed and irrigated lands without compromising water quality and quantity. The SWMCN Subprogramme has launched two new Coordinated Research Projects (CRPs) in 2013 which aim to address major soil, water and nutrient management issues for climate smart agriculture, and integrated cropping livestock agriculture. Conservation of natural resources for food security is an important consideration in climate smart agriculture. There is increasing attention to land resource management for food security throughout the world. The Global Soil Week entitled 'Losing Ground?' convened in Berlin, Germany, from 27-31 October 2013, with more than 450 participants (scientists, policy makers and land managers) from over 70 countries has raised major concerns about land degradation which affects soil fertility, crop nutrition, food productivity, water quantity and quality. It has highlighted the importance of climatesoil- water nexus in food security. Besides CRPs, the SWMCN Subprogramme also provided technical support to 52 Technical Cooperation Projects (TCPs) in 2013 and about 30 new TCPs will be implemented in 2014-2015. The SWMCN Laboratory of the SWMCN Subprogramme has also provided support to CRPs through research and development in soil carbon sequestration, GHG emissions and agricultural water

  5. What is Process Tracing actually tracing?

    DEFF Research Database (Denmark)

    Beach, Derek; Pedersen, Rasmus Brun

    and when we use PT case studies. First, there are differences in what we are actually tracing in the three variants, resulting in different methodological prescriptions for each variant. Second, the types of inferences being made are also different; the variants therefore have different analytical uses...

  6. Interactive Stable Ray Tracing

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Salvi, Marco; Kolb, Craig

    2017-01-01

    Interactive ray tracing applications running on commodity hardware can suffer from objectionable temporal artifacts due to a low sample count. We introduce stable ray tracing, a technique that improves temporal stability without the over-blurring and ghosting artifacts typical of temporal post-pr...

  7. Color Addition and Subtraction Apps

    Science.gov (United States)

    Ruiz, Frances; Ruiz, Michael J.

    2015-01-01

    Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step…

  8. Nuclear traces in glass

    International Nuclear Information System (INIS)

    Segovia A, M. de N.

    1978-01-01

    The charged particles produce, in dielectric materials, physical and chemical effects which make evident the damaged zone along the trajectory of the particle. This damaged zone is known as the latent trace. The latent traces can be enlarged by an etching of the detector material. This treatment attacks preferently the zones of the material where the charged particles have penetrated, producing concavities which can be observed through a low magnification optical microscope. These concavities are known as developed traces. In this work we describe the glass characteristics as a detector of the fission fragments traces. In the first chapter we present a summary of the existing basic theories to explain the formation of traces in solids. In the second chapter we describe the etching method used for the traces development. In the following chapters we determine some chatacteristics of the traces formed on the glass, such as: the development optimum time; the diameter variation of the traces and their density according to the temperature variation of the detector; the glass response to a radiation more penetrating than that of the fission fragments; the distribution of the developed traces and the existing relation between this ditribution and the fission fragments of 252 Cf energies. The method which has been used is simple and cheap and can be utilized in laboratories whose resources are limited. The commercial glass which has been employed allows the registration of the fission fragments and subsequently the realization of experiments which involve the counting of the traces as well as the identification of particles. (author)

  9. Food and environmental protection newsletter. V.1, no. 2

    International Nuclear Information System (INIS)

    1998-06-01

    The activities of the Food and Environmental Protection Section are gaining momentum through the combined strength of the staff members of the former Food Preservation and Agrochemical and Residues Section. In addition to the encouraging outcomes of existing CRPs in the field of food irradiation and pesticides, this issue reports two new CRPs which have either been initiated or are in the processes of being initiated. Any research institutes which wish to participate in any of these two new CRPs should contact us as soon as possible. The status of various on going CRPs and new CRPs is also described in this issue. The activities of the FAO/IAEA Training and Reference Centre of Food and Pesticide Control for this year are described in this issue. Reports of some activities which have just been implemented during the first half of 1998, including the Workshop on Introduction of QA/QC Principles in Pesticide Residue Analysis held in Hungary in March, are summarized in this issue

  10. Analysis of the distributions of hourly NO2 concentrations contributing to annual average NO2 concentrations across the European monitoring network between 2000 and 2014

    Science.gov (United States)

    Malley, Christopher S.; von Schneidemesser, Erika; Moller, Sarah; Braban, Christine F.; Hicks, W. Kevin; Heal, Mathew R.

    2018-03-01

    Exposure to nitrogen dioxide (NO2) is associated with negative human health effects, both for short-term peak concentrations and from long-term exposure to a wider range of NO2 concentrations. For the latter, the European Union has established an air quality limit value of 40 µg m-3 as an annual average. However, factors such as proximity and strength of local emissions, atmospheric chemistry, and meteorological conditions mean that there is substantial variation in the hourly NO2 concentrations contributing to an annual average concentration. The aim of this analysis was to quantify the nature of this variation at thousands of monitoring sites across Europe through the calculation of a standard set of chemical climatology statistics. Specifically, at each monitoring site that satisfied data capture criteria for inclusion in this analysis, annual NO2 concentrations, as well as the percentage contribution from each month, hour of the day, and hourly NO2 concentrations divided into 5 µg m-3 bins were calculated. Across Europe, 2010-2014 average annual NO2 concentrations (NO2AA) exceeded the annual NO2 limit value at 8 % of > 2500 monitoring sites. The application of this chemical climatology approach showed that sites with distinct monthly, hour of day, and hourly NO2 concentration bin contributions to NO2AA were not grouped into specific regions of Europe, furthermore, within relatively small geographic regions there were sites with similar NO2AA, but with differences in these contributions. Specifically, at sites with highest NO2AA, there were generally similar contributions from across the year, but there were also differences in the contribution of peak vs. moderate hourly NO2 concentrations to NO2AA, and from different hours across the day. Trends between 2000 and 2014 for 259 sites indicate that, in general, the contribution to NO2AA from winter months has increased, as has the contribution from the rush-hour periods of the day, while the contribution from

  11. Production of N2O5and ClNO2through Nocturnal Processing of Biomass-Burning Aerosol.

    Science.gov (United States)

    Ahern, Adam T; Goldberger, Lexie; Jahl, Lydia; Thornton, Joel; Sullivan, Ryan C

    2018-01-16

    Biomass burning is a source of both particulate chloride and nitrogen oxides, two important precursors for the formation of nitryl chloride (ClNO 2 ), a source of atmospheric oxidants that is poorly prescribed in atmospheric models. We investigated the ability of biomass burning to produce N 2 O 5 (g) and ClNO 2 (g) through nocturnal chemistry using authentic biomass-burning emissions in a smog chamber. There was a positive relationship between the amount of ClNO 2 formed and the total amount of particulate chloride emitted and with the chloride fraction of nonrefractory particle mass. In every fuel tested, dinitrogen pentoxide (N 2 O 5 ) formed quickly, following the addition of ozone to the smoke aerosol, and ClNO 2 (g) production promptly followed. At atmospherically relevant relative humidities, the particulate chloride in the biomass-burning aerosol was rapidly but incompletely displaced, likely by the nitric acid produced largely by the heterogeneous uptake of N 2 O 5 (g). Despite this chloride acid displacement, the biomass-burning aerosol still converted on the order of 10% of reacted N 2 O 5 (g) into ClNO 2 (g). These experiments directly confirm that biomass burning is a potentially significant source of atmospheric N 2 O 5 and ClNO 2 to the atmosphere.

  12. Application of electrochemically deposited nanostructured ZnO layers on quartz crystal microbalance for NO2 detection

    International Nuclear Information System (INIS)

    St. Kliment Ohridski N° 8, Sofia 1756 (Bulgaria))" data-affiliation=" (UCTM bul. St. Kliment Ohridski N° 8, Sofia 1756 (Bulgaria))" >Georgieva, B; Petrov, M; Lovchinov, K; Ganchev, M; Dimova-Malinovska, D; Georgieva, V

    2014-01-01

    The research was fixed on sensing behavior of ZnO nanostructured (NS) films to NO 2 concentrations in the environment. The ZnO NS layers are deposited by electrochemical method on quartz resonators with Au electrodes. The sorption properties of ZnO layers were defined by measuring the resonant frequency shift (Δf) of the QCM-ZnO structure for different NO 2 concentrations. The measurements were based on the correlation between the frequency shift of the QCM and additional mass loading (Δm) on the resonator calculated using Sauerbrey equation for the AT-cut quartz plate. Frequency – Time Characteristics (FTCs) of the samples were measured as a function of different NO 2 concentrations in order to define the sorption abilities of ZnO layers. The experiments were carried out on a special set up in a dynamical regime. From FTCs the response and the recovery times of the QCM-ZnO structure were measured with varying NO 2 . Frequency shift changed from 23 Hz to 58Hz when NO 2 was varied in the range of 250ppm – 5000ppm. The process of sorption was estimated as reversible and the sorption as physical. The obtained results demonstrated that QCM covered with the electrochemically deposited nanostructured ZnO films can be used as application in NO 2 sensors

  13. Food and environmental protection newsletter. Vol. 3, No. 2

    International Nuclear Information System (INIS)

    2001-07-01

    Significant progress on international standard setting has been made in recent months. Firstly, the Codex General Standard for Irradiated Foods was accepted for amendment at Step 5 by the 33 rd Session of the Codex Committee on Food Additives and Contaminants (CCFAC), The Hague, The Netherlands, 12-16 March 2001, by removing the maximum dose limit of 10 kGy. Secondly, the 3 rd Session of the Interim Commission on Phytosanitary Measures (ICPM), the standard setting body of the International Plant Protection Convention (IPPC), Rome, Italy, 2-6 April 2001 agreed to develop a new international standard on irradiation as a phytosanitary measure. Finally, the Codex Committees on Pesticide Residues and on Veterinary Drug Residues agreed to accept the Guidelines on Single Laboratory Method Validation for further development as their standards. It is expected that all these developments will lead to international standards in respective fields by 2003. Following a positive development on certification of irradiation as a .sanitary and phytosanitary treatment in Asia and the Pacific through a regional workshop held in Sydney, Australia in December 2000 (see details in this issue), another regional workshop on the same subject will take place in Rio de Janeiro, Brazil for the benefit of Latin American countries. A new Co-ordinated Research Project (CRP) on Irradiation to Ensure Hygienic Quality of Fresh, Pre-Cut Fruits and Vegetables and Other Minimally Processed Food of Plant Origin is now being implemented jointly with the Pan American Health Organization. The first Research Co-ordination Meeting (RCM) of this CRP will be held later this year. Progress made through RCMs on Irradiation as a Phytosanitary Treatment of Food and Agricultural Commodities, on Transfer Factors of Radionuclides from Soil to Reference Plants and on Quality Control of Pesticide Products, held during the past six months, is reported in this issue

  14. Soils Newsletter, Vol. 35, No. 2, January 2013

    International Nuclear Information System (INIS)

    2013-01-01

    food security in arid and semi-arid regions'; (ii) 'Agro-ecosystem carbon and nutrient budgeting to assess land resource sustainability for food and biofuel production in marginal lands'; and (iii) 'Optimizing soil and water resource efficiency in integrated cropping - livestock production systems'. These CMs will act as major springboards for the development of three Coordinated Research Projects (CRPs) in 2013, which aim to address major soil, water and nutrient management issues for climate smart agriculture, sustainable multifunctional food/biofuel production systems and integrated cropping - livestock agriculture. Currently there are five ongoing CRPs in the SWMCN Subprogramme, with the CRP D1.20.09 entitled: 'Managing Irrigation Water to Enhance Crop Productivity under Water- Limiting Conditions: a Role for Isotopic Techniques (D1.20.09)' concluding in July 2012. The technical document (TECDOC) summarizing the results of this 5-year CRP is in the initial stage of preparation. In addition to the CRPs, the SWMCN Subprogramme also provided technical support to 52 Technical Cooperation Projects (TCPs) throughout the world in 2012. Of these TCPs, ten are regional projects, which include (a) four in Latin America on soil erosion - soil fertility - soil nutrient management, (b) four in the Asia-Pacific region on soil fertility, land productivity and land degradation and (c) two in Africa on small scale irrigation for high value crops and conservation agriculture practices. The SWMCN Laboratory of the SWMCN Subprogramme has also provided support to CRPs through research and development in soil carbon sequestration, greenhouse gas emissions and agricultural water management. In addition, 43 fellows were trained in the SWMCN Laboratory during 2012. The challenges and opportunities of the SWMCN Subprogramme are entering a very exciting phase, with increasing focus and awareness of policy makers and farming communities around the world on the management of land and

  15. Food and environmental protection newsletter. Vol. 6, No. 2

    International Nuclear Information System (INIS)

    2004-06-01

    This issue of our newsletter also includes a summary of the consideration of the revised Codex Guideline Levels for Radionuclides in Foods for Use in International Trade under our Feature Article. The Guideline Levels were considered by the 36th Session of the Codex Committee on Food Additives and Contaminants (CCFAC), which was held in Rotterdam, The Netherlands, from 22-26 March 2004. We are pleased to report that the full plenary session of the CCFAC agreed to forward the proposed draft Revised Guideline Levels for Radionuclides in Foods for Use in International Trade to the forthcoming 27th Session (June 2004) of the Joint FAO/WHO Codex Alimentarius Commission for preliminary adoption. It is anticipated that the technical assistance provided by our colleagues in the Division of Radiation and Waste Safety will help to ensure the successful final adoption of the Guideline Levels by the 28th Session of the Codex Alimentarius Commission in 2005. It is recalled from the January 2004 issue of our Newsletter, the 20th Meeting (October 2003) of the Joint FAO/IAEA/WHO International Consultative Group on Food Irradiation (ICGFI) agreed that a new successor organization would not be created and that prior to the expiration of the ICGFI mandate on 8 May 2004, a working group consisting of government-designated experts would meet in Vienna in early 2004 to discuss and provide advice on future activities related to the application of irradiation for sanitary and phytosanitary purposes. The Report on The International Consultative Group on Food Irradiation (see page 13) provides a summary of the ICGFI Working Group deliberations, including its conclusions and recommendations to its sponsoring organizations and ICGFI member governments. These working group recommendations led in part to the holding of a successful Consultants Meeting on the Use of Ionising Radiation as a Quarantine Treatment which, among other responsibilities, proposed specific irradiation doses for

  16. Soils newsletter, Vol. 30, No. 2, January 2008

    International Nuclear Information System (INIS)

    2008-01-01

    will provide the SWMCN subprogramme with additional opportunities for serving the Member States through an increasing numbers of TCPs in agricultural water management and soil conservation. Three RCMs will be held in 2008: Soil, Water and Nutrient Management for Conservation Agriculture (D1.50.09), Selection and Evaluation of Food (Cereal and Legume) Crop Genotypes Tolerant to Low Nitrogen and Phosphorus Soils Through the Use of Isotopic and Nuclear-related Techniques (D1.50.10) and Selection for Greater Agronomic Water Use Efficiency in Wheat and Rice Using Carbon Isotope Discrimination (D1.20.08). The success of these RCMs will depend on the commitment of contract holders, technical contractors, agreement holders and the support of Member States acting as RCM hosts

  17. Evidence for the presence of the 802.7/cm band Q branch of HO2NO2 in high resolution solar absorption spectra of the stratosphere

    Science.gov (United States)

    Rinsland, C. P.; Zander, R.; Farmer, C. B.; Norton, R. H.; Brown, L. R.; Russell, J. M., III; Park, J. H.

    1986-08-01

    Stratospheric solar absorption spectra recorded at ≡0.01 cm-1 resolution by the ATMOS (Atmospheric Trace Molecule Spectroscopy) Fourier transform spectrometer during the Spacelab 3 Shuttle mission show a weak absorption feature covering ≡802.5 - 803.3 cm-1. The authors identify this feature as the unresolved Q branch of the 802.7 cm-1 band of HO2NO2 and report profiles for 31°N and 47°S.

  18. Trace minerals and livestock: not too much not too little.

    Science.gov (United States)

    López-Alonso, Marta

    2012-01-01

    The new approaches of the animal production systems make managing the mineral nutrition a challenge. Versus the excessive, trace mineral supply in intensively managed livestock, well above the physiological requirements, is the no trace mineral supplementation of organic systems, which become highly dependent on trace minerals in the soil. Nowadays, in addition to the animal health perspective, trace mineral nutrition must be environment friendly and allow getting mineral-enriched animal products. We are in a new scenario, where a balance between animal trace mineral needs and limits is needed. This papers focuses on different aspects that will help us to enter a critical dialogue in relation to animal-human-environment.

  19. Editor's welcome, PORTAL Vol. 3, No. 2, July 2006

    Directory of Open Access Journals (Sweden)

    Paul Allatson

    2006-09-01

    Full Text Available The second issue of PORTAL Journal of Multidisciplinary International Studies for 2006 features a special selection of essays grouped under the title ‘Women in Asia’ and guest-edited by Devleena Ghosh and Barbara Leigh, both from the University of Technology Sydney. The essays in this special issue had their first incarnations at the Eighth Women in Asia Conference, ‘Shadow Lines’, organised by the Women’s Caucus of the Asian Studies Association of Australia and the University of Technology Sydney (convened by Ghosh and Leigh, and held at the University of Technology Sydney from 26 to the 28 September 2005. Aiming self-consciously and tacitly to toy with, and dispute, the historical and discursive valencies accruing to the key, twined terms ‘women’ and ‘Asia’, the ten essays grouped here combine to form a rich repository of contemporary research about the status of women in many parts of that vast, arguably incoherent, geocultural space called Asia. All of the contributing authors thus ‘attempt to unsettle discourses about limits,’ to cite from co-editor Devleena Ghosh’s opening paper. That attempt is far from straightforward, as Ghosh elaborates: ‘That lines, borders and boundaries exist, whether of prejudice, politics, economics, or culture, is undeniable. But how do we analyse these issues without ossifying them, creating implacable alterities that refuse the liminal spaces that people occupy?’ Multivalent solutions are called for, Ghosh suggests, and these are to be found not simply in ‘counter-politics and interventions’, but also through the excavation and recognition of multiple subjectivities from/in ‘a thousand plateaus, [and] felt and experienced through the body, historical landscapes, domestic spaces, through performance as well as through the realm of the imaginary, in the impact of ideals and the weight of history’. In addition to the special section on ‘Women in Asia’, this edition of PORTAL

  20. Food additives

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002435.htm Food additives To use the sharing features on this page, please enable JavaScript. Food additives are substances that become part of a food ...

  1. Balloon-borne limb profiling of UV/vis skylight radiances, O3, NO2, and BrO: technical set-up and validation of the method

    Directory of Open Access Journals (Sweden)

    F. Weidner

    2005-01-01

    Full Text Available A novel light-weight, elevation scanning and absolutely calibrated UV/vis spectrometer and its application to balloon-borne limb radiance and trace gas profile measurements is described. Its performance and the novel method of balloon-borne UV/vis limb trace gas measurements has been tested against simultaneous observations of the same atmospheric parameters available from either (a in-situ instrumentation (cf., by an electrochemical cell (ECC ozone sonde also deployed aboard the gondola or (b trace gas profiles inferred from UV/vis/near IR solar occultation measurements performed on the same payload. The novel technique is also cross validated with radiative transfer modeling. Reasonable agreement is found (a between measured and simulated limb radiances and (b inferred limb O3, NO2, and BrO and correlative profile measurements when properly accounting for all relevant atmospheric parameters (temperature, pressure, aerosol extinction, and major absorbers.

  2. Assimilation of satellite NO2 observations at high spatial resolution using OSSEs

    Science.gov (United States)

    Liu, Xueling; Mizzi, Arthur P.; Anderson, Jeffrey L.; Fung, Inez Y.; Cohen, Ronald C.

    2017-06-01

    Observations of trace gases from space-based instruments offer the opportunity to constrain chemical and weather forecast and reanalysis models using the tools of data assimilation. In this study, observing system simulation experiments (OSSEs) are performed to investigate the potential of high space- and time-resolution column measurements as constraints on urban NOx emissions. The regional chemistry-meteorology assimilation system where meteorology and chemical variables are simultaneously assimilated is comprised of a chemical transport model, WRF-Chem, the Data Assimilation Research Testbed, and a geostationary observation simulator. We design OSSEs to investigate the sensitivity of emission inversions to the accuracy and uncertainty of the wind analyses and the emission updating scheme. We describe the overall model framework and some initial experiments that point out the first steps toward an optimal configuration for improving our understanding of NOx emissions by combining space-based measurements and data assimilation. Among the findings we describe is the dependence of errors in the estimated NOx emissions on the wind forecast errors, showing that wind vectors with a RMSE below 1 m s-1 allow inference of NOx emissions with a RMSE of less than 30 mol/(km2 × h) at the 3 km scale of the model we use. We demonstrate that our inference of emissions is more accurate when we simultaneously update both NOx emissions and NOx concentrations instead of solely updating emissions. Furthermore, based on our analyses, we recommend carrying out meteorology assimilations to stabilize NO2 transport from the initial wind errors before starting the emission assimilation. We show that wind uncertainties (calculated as a spread around a mean wind) are not important for estimating NOx emissions when the wind uncertainties are reduced below 1.5 m s-1. Finally, we present results assessing the role of separate vs. simultaneous chemical and meteorological assimilation in a model

  3. Traces of Drosophila Memory

    Science.gov (United States)

    Davis, Ronald L.

    2012-01-01

    Summary Studies using functional cellullar imaging of living flies have identified six memory traces that form in the olfactory nervous system after conditioning with odors. These traces occur in distinct nodes of the olfactory nervous system, form and disappear across different windows of time, and are detected in the imaged neurons as increased calcium influx or synaptic release in response to the conditioned odor. Three traces form at, or near acquisition and co-exist with short-term behavioral memory. One trace forms with a delay after learning and co-exists with intermediate-term behavioral memory. Two traces form many hours after acquisition and co-exist with long-term behavioral memory. The transient memory traces may support behavior across the time-windows of their existence. The experimental approaches for dissecting memory formation in the fly, ranging from the molecular to the systems, make it an ideal system for dissecting the logic by which the nervous system organizes and stores different temporal forms of memory. PMID:21482352

  4. Factors associated with NO2 and NOX concentration gradients near a highway

    Science.gov (United States)

    Richmond-Bryant, J.; Snyder, M. G.; Owen, R. C.; Kimbrough, S.

    2018-02-01

    The objective of this research is to learn how the near-road gradient, in which NO2 and NOX (NO + NO2) concentrations are elevated, varies with changes in meteorological and traffic variables. Measurements of NO2 and NOX were obtained east of I-15 in Las Vegas and fit to functions whose slopes (dCNO2/dx and dCNOX/dx, respectively) characterize the size of the near-road zone where NO2 and NOX concentrations from mobile sources on the highway are elevated. These metrics were used to learn about the near-road gradient by modeling dCNO2/dx and dCNOX/dx as functions of meteorological variables (e.g., wind direction, wind speed), traffic (vehicle count), NOX concentration upwind of the road, and O3 concentration at two fixed-site ambient monitors. Generalized additive models (GAM) were used to model dCNO2/dx and dCNOX/dx versus the independent variables because they allowed for nonlinearity of the variables being compared. When data from all wind directions were included in the analysis, variability in O3 concentration comprised the largest proportion of variability in dCNO2/dx, followed by variability in wind direction. In a second analysis constrained to winds from the west, variability in O3 concentration remained the largest contributor to variability in dCNO2/dx, but the relative contribution of variability in wind speed to variability in dCNO2/dx increased relative to its contribution for the all-wind analysis. When data from all wind directions were analyzed, variability in wind direction was by far the largest contributor to variability in dCNOX/dx, with smaller contributions from hour of day and upwind NOX concentration. When only winds from the west were analyzed, variability in upwind NOX concentration, wind speed, hour of day, and traffic count all were associated with variability in dCNOX/dx. Increases in O3 concentration were associated with increased magnitude near-road dCNO2/dx, possibly shrinking the zone of elevated concentrations occurring near roads

  5. Neutron activation analysis on source of raw material of terracotta warriors and horses in No.2 pit of Qin Shihuang's mausoleum

    International Nuclear Information System (INIS)

    Li Guoxia; Zhao Weijuan; Gao Zhengyao; Xie Jianzhong; Han Guohe

    2002-01-01

    32 trace element contents in each sample are measured by neutron activation analysis for the selected that 19 samples of terracotta warriors and horses from No.2 pit of Emperor Qin shihuang's Mausoleum, 20 samples clay nearby Qin's Mausoleum and 2 samples of Yaozhou porcelain bodies. The trend cluster analysis diagram is obtained after sorting the data. The results show that the samples from the No.2 pit of Emperor Qin Shihuang's Mausoleum have a close relationship with the clay samples from the neighborhood of the Mausoleum. Consequently, the source of raw materials of the terracotta warriors and horses may come from some places nearby the Mausoleum, the kiln sites may be also neighborhood of the Mausoleum. There is also a preliminary study on the relationship between the sealing earth of the Mausoleum, rammed earth and backfill of the No.2 pit and the clay from the nearby place

  6. The Utility of the OMI HCHO and NO2 Data Products in Air Quality Decision- Making Activities

    Science.gov (United States)

    Duncan, Bryan N.

    2010-01-01

    We will present three related air quality applications of the OMI HCHO (formaldehyde) and NO2 (nitrogen dioxide) data products, which we us to support mission planning of an OMI-like instrument for the proposed GEO-CAPE satellite that has as one of its objectives to study air quality from space. First, we will discuss a novel and practical application of the data products to the "weight of evidence" in the air quality decision-making process (e.g., State Implementation Plan (SIP)) for a city, region, or state to demonstrate that it is making progress toward attainment of the National Ambient Air Quality Standard (NAAQS) for ozone. Any trend, or lack thereof, in the observed OMI HCHO/NO2, which we use as an air quality indicator, may support that an emission control strategy implemented to reduce ozone is or is not occurring for a metropolitan area. Second, we will discuss how we use variations in the OMI HCHO product as a proxy for variability in the biogenic hydrocarbon, isoprene, which is an important player for the formation of high levels of ozone and the dominant source of HCHO in the eastern U.S. Third, we will discuss the variability of NO2 in the U.S. as indicated by the OMI NO2 product. In addition, we will show the impact of the 2005 hurricanes on pollutant emissions, including those associated with the intensive oil extraction and refining activities, in the Gulf of Mexico region using the OMI NO2 product. The variability of HCHO and NO2 as indicated by OMI helps us to understand changes in the OMI HCHO/NO2 and the implications for ozone formation.

  7. Radon and NO2levels and related environmental factors in 100 underground subway platforms over two-year period.

    Science.gov (United States)

    Hwang, Sung Ho; Park, Jae Bum; Park, Wha Me

    2018-01-01

    In this study, the environmental factors that affect radon (Rn) and nitrogen dioxide (NO 2 ) levels in subway-station underground platforms are evaluated, and the outdoor NO 2 levels are compared with those obtained for the underground platforms. The Rn and NO 2 levels from May 2013 to September 2015 are determined for lines 1-4 of the Seoul Metro, via calculation of the arithmetic means of the Rn and NO 2 levels with their standard deviations (SDs). The underground Rn levels in 2013 are found to be significantly higher than those recorded in 2015 for the Seoul Metro. In addition, the Rn levels are related to the station depth and construction year. Further, the underground NO 2 levels are shown to be significantly higher than the outdoor levels for all four Seoul Metro subway lines. The Rn levels are also found to vary significantly between months, and are shown to increase gradually with depth from 8 to 20 m. The Rn levels are also higher for stations constructed in the 1980s. Therefore, stricter monitoring of Rn level may be required for stations constructed in the 1980s and/or having platform depths within the 8-20 m range. Island-type platform stations based on granite areas may also require careful attention. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. 7 CFR 51.2754 - U.S. No. 2 Virginia.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. No. 2 Virginia. 51.2754 Section 51.2754... STANDARDS) United States Standards for Shelled Virginia Type Peanuts Grades § 51.2754 U.S. No. 2 Virginia. “U.S. No. 2 Virginia” consists of shelled Virginia type peanut kernels of similar varietal...

  9. American Recovery and Reinvestment Act: North Fork Skokomish Powerhouse at Cushman No. 2 Dam

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Steve [DBA Tacoma Power, WA (United States); McCarty, Patrick [DBA Tacoma Power, WA (United States)

    2013-09-30

    The objective of this project was to add generating capacity on an in-stream flow release at Tacoma Power's Cushman hydroelectric project, Cushman No. 2 Dam, FERC Project P-460. The flow that is being used to generate additional electricity was being discharged from a valve at the base of the dam without recovery of the energy. A second objective to the project was to incorporate upstream fish passage by use of a fish collection structure attached to the draft tubes of the hydroelectric units. This will enable reintroduction of native anadromous fish above the dams which have blocked fish passage since the late 1920's. The project was funded in part by the American Recovery and Reinvestment Act through the Department of Energy, Office of Energy, Efficiency and Renewable Energy, Wind and Water Power Program.

  10. Additive manufacturing.

    Science.gov (United States)

    Mumith, A; Thomas, M; Shah, Z; Coathup, M; Blunn, G

    2018-04-01

    Increasing innovation in rapid prototyping (RP) and additive manufacturing (AM), also known as 3D printing, is bringing about major changes in translational surgical research. This review describes the current position in the use of additive manufacturing in orthopaedic surgery. Cite this article: Bone Joint J 2018;100-B:455-60.

  11. Experience with novel technologies for direct measurement of atmospheric NO2

    Science.gov (United States)

    Hueglin, Christoph; Hundt, Morten; Mueller, Michael; Schwarzenbach, Beat; Tuzson, Bela; Emmenegger, Lukas

    2017-04-01

    Nitrogen dioxide (NO2) is an air pollutant that has a large impact on human health and ecosystems, and it plays a key role in the formation of ozone and secondary particulate matter. Consequently, legal limit values for NO2 are set in the EU and elsewhere, and atmospheric observation networks typically include NO2 in their measurement programmes. Atmospheric NO2 is principally measured by chemiluminescence detection, an indirect measurement technique that requires conversion of NO2 into nitrogen monoxide (NO) and finally calculation of NO2 from the difference between total nitrogen oxides (NOx) and NO. Consequently, NO2 measurements with the chemiluminescence method have a relatively high measurement uncertainty and can be biased depending on the selectivity of the applied NO2 conversion method. In the past years, technologies for direct and selective measurement of NO2 have become available, e.g. cavity attenuated phase shift spectroscopy (CAPS), cavity enhanced laser absorption spectroscopy and quantum cascade laser absorption spectrometry (QCLAS). These technologies offer clear advantages over the indirect chemiluminescence method. We tested the above mentioned direct measurement techniques for NO2 over extended time periods at atmospheric measurement stations and report on our experience including comparisons with co-located chemiluminescence instruments equipped with molybdenum as well as photolytic NO2 converters. A still open issue related to the direct measurement of NO2 is instrument calibration. Accurate and traceable reference standards and NO2 calibration gases are needed. We present results from the application of different calibration strategies based on the use of static NO2 calibration gases as well as dynamic NO2 calibration gases produced by permeation and by gas-phase titration (GPT).

  12. Efficacy of passive sampler collection for atmospheric NO2 isotopes under simulated environmental conditions.

    Science.gov (United States)

    Coughlin, Justin G; Yu, Zhongjie; Elliott, Emily M

    2017-07-30

    Nitrogen oxides or NO x (NO x = NO + NO 2 ) play an important role in air quality, atmospheric chemistry, and climate. The isotopic compositions of anthropogenic and natural NO 2 sources are wide-ranging, and they can be used to constrain sources of ambient NO 2 and associated atmospheric deposition of nitrogen compounds. While passive sample collection of NO 2 isotopes has been used in field studies to determine NO x source influences on atmospheric deposition, this approach has not been evaluated for accuracy or precision under different environmental conditions. The efficacy of NO 2 passive sampler collection for NO 2 isotopes was evaluated under varied temperature and relative humidity (RH) conditions in a dynamic flux chamber. The precision and accuracy of the filter NO 2 collection as nitrite (NO 2 - ) for isotopic analysis were determined using a reference NO 2 gas tank and through inter-calibration with a modified EPA Method 7. The bacterial denitrifer method was used to convert 20 μM of collected NO 2 - or nitrate (NO 3 - ) into N 2 O and was carried out on an Isoprime continuous flow isotope ratio mass spectrometer. δ 15 N-NO 2 values determined from passive NO 2 collection, in conditions of 11-34 °C, 1-78% RH, have an overall accuracy and precision of ±2.1 ‰, and individual run precision of ±0.6 ‰. δ 18 O-NO 2 values obtained from passive NO 2 sampler collection, under the same conditions, have an overall precision of ± 1.3 ‰. Suitable conditions for passive sampler collection of NO 2 isotopes are in environments ranging from 11 to 34 °C and 1 to 78% RH. The passive NO 2 isotope measurement technique provides an accurate method to determine variations in atmospheric δ 15 N-NO 2 values and a precise method for determining atmospheric δ 18 O-NO 2 values. The ability to measure NO 2 isotopes over spatial gradients at the same temporal resolution provides a unique perspective on the extent and seasonality of fluctuations in atmospheric NO 2

  13. Possible causes of stratospheric NO2 trends observed at Lauder, New Zealand

    Science.gov (United States)

    Fish, D. J.; Roscoe, H. K.; Johnston, P. V.

    2000-10-01

    A recently published analysis of slant columns of NO2 observed at twilight at 45°S has identified trends of about 5%/decade between 1980 and 1998. This is twice the trend in tropospheric N2O, which is the source of stratospheric NO2. By means of a column photochemical model, we explore the sensitivity of NO2 to the observed trends in stratospheric temperature, O3 and H2O. The resulting calculated trends in NO2 are smaller than observed, and we cannot force agreement by varying the ozone or temperature trends. The calculated sensitivity of NO2 to stratospheric aerosol is large, and a 20% per decade decrease in aerosol surface area creates agreement. We conclude that a small residual in the statistical fit of aerosol to the NO2 measurements may remain, and is a likely cause of the trends found in the NO2 measurements.

  14. Social factors associated with nitrogen dioxide (NO2) exposure during pregnancy: the INMA-Valencia project in Spain.

    Science.gov (United States)

    Llop, Sabrina; Ballester, Ferran; Estarlich, Marisa; Iñiguez, Carmen; Ramón, Rosa; Gonzalez, Ma Carmen; Murcia, Mario; Esplugues, Ana; Rebagliato, Marisa

    2011-03-01

    Numerous studies have focused on the effects of exposure to air pollution on health; however, certain subsets of the population tend to be more exposed to such pollutants depending on their social or demographic characteristics. In addition, exposure to toxicants during pregnancy may play a deleterious role in fetal development as fetuses are especially vulnerable to external insults. The present study was carried out within the framework of the INMA (Infancia y Medio Ambiente or Childhood and the Environment) multicenter cohort study with the objective of identifying the social, demographic, and life-style factors associated with nitrogen dioxide (NO(2)) exposure in the subjects in the cohort. The study comprised 785 pregnant women who formed part of the INMA cohort in Valencia, Spain. Outdoor levels of NO(2) were measured at 93 sampling sites spread over the study area during four different sampling periods lasting 7 days each. Multiple regression models were used for mapping outdoor NO(2) throughout the area. Individual exposure was assigned as: 1) the estimated outdoor NO(2) levels at home, and 2) the average of estimated outdoor NO(2) levels at home and work, weighted according to the time spent in each environment. The subjects' socio-demographic and life-style information was obtained through a questionnaire. In the multiple linear analyses, the outdoor NO(2) levels assigned to each home were taken to be the dependent variable. Other variables included in the model were: age, country of origin, smoking during pregnancy, parity, season of the year, and social class. These same variables remained in the model when the dependent variable was changed to the NO(2) levels adjusted for the subjects' time-activity patterns. We found that younger women, those coming from Latin American countries, and those belonging to the lower social strata were exposed to higher NO(2) levels, both as measured outside their homes as well as when time-activity patterns were taken

  15. Eddy covariance fluxes of the NO-O3-NO2 triad above the forest canopy at the ATTO Site in the Amazon Basin

    Science.gov (United States)

    Tsokankunku, Anywhere; Wolff, Stefan; Sörgel, Matthias; Berger, Martina; Zelger, Michael; Dlugi, Ralf

    2017-04-01

    Nitrogen monoxide (NO) and nitrogen dioxide (NO2) (denoted together as NOx) determine the abundance of the tropospheric oxidants OH, O3 and NO3 that regulate atmospheric self-cleaning. The three reactive trace gases NO, NO2 and O3 undergo a series of interconnected photochemical reactions and are often referred to as the NO-O3-NO2 triad. Ozone deposition is mainly controlled by stomatal uptake, thus contributes to oxidative stress for the plants. Similarly, nitrogen dioxide from above or below the canopy is deposited to leaves through stomatal uptake. NO emissions from soils contribute to above canopy O3 formation and accelerate OH recycling. Therefore, quantification of the exchange fluxes of these species between the atmosphere and the biosphere are important for atmospheric chemistry and ecosystem research as well. The eddy covariance method is state of the art for direct measurements of ecosystem fluxes of trace gases. Eddy covariance measurements of NOx in pristine environments are rare because of lack of availability of instruments with the required precision to resolve concentrations characteristic of these environments. The Amazon Tall Tower Observatory (ATTO) is located in a pristine rainforest environment in the Amazon basin about 150 km northeast of the city of Manaus. It is the ideal site for studying the biosphere-atmosphere exchange of the NO-O3-NO2 triad, being largely undisturbed by anthropogenic sources. During an intensive measurement campaign in November 2015 at the ATTO site, measurements of NO, NO2 and O3 were carried out at 42 m above ground level on the 80 m walk-up tower with a fast (5 Hz) and sensitive (gas profile system which has been operational at the site since 2012. From these measurements, we present eddy covariance fluxes of the NO-O3-NO2 triad. We relate the fluxes to the canopy-atmosphere exchange of the trace gases and other scalars using the profile data along the tower. Chemical and turbulent transport timescales of the triad

  16. Intraoral gothic arch tracing.

    Science.gov (United States)

    Rubel, Barry; Hill, Edward E

    2011-01-01

    In order to create optimum esthetics, function and phonetics in complete denture fabrication, it is necessary to record accurate maxillo-mandibular determinants of occlusion. This requires clinical skill to establish an accurate, verifiable and reproducible vertical dimension of occlusion (VDO) and centric relation (CR). Correct vertical relation depends upon a consideration of several factors, including muscle tone, inter-dental arch space and parallelism of the ridges. Any errors made while taking maxillo-mandibular jaw relation records will result in dentures that are uncomfortable and, possibly, unwearable. The application of a tracing mechanism such as the Gothic arch tracer (a central bearing device) is a demonstrable method of determining centric relation. Intraoral Gothic arch tracers provide the advantage of capturing VDO and CR in an easy-to-use technique for practitioners. Intraoral tracing (Gothic arch tracing) is a preferred method of obtaining consistent positions of the mandible in motion (retrusive, protrusive and lateral) at a comfortable VDO.

  17. Trace analysis by TXRF

    International Nuclear Information System (INIS)

    Hockett, R.S.

    1995-01-01

    Total reflection X-Ray Fluorescence (TXRF) originally was developed for trace analysis of small residues but has become a widespread method for measuring trace surface metal contamination an semiconductor substrates. It is estimated that approximately 100 TXRF instruments are in se in the semiconductor industry worldwide, and approximately half that for residue analysis x analytical laboratories. TXRF instrumentation is available today for reaching detection limits d the order of 10 9 atoms/cm 2 . This review emphasizes some of the more recent developments in TXRF for trace analysis, in particular with the use of synchrotron x-ray sources (SR-TXRF). There is some promise of reaching 10 7 atoms/cm 2 detection limits for surface analysis of semi-conductor substrates. 19 refs

  18. Development of a custom OMI NO2 data product for evaluating biases in a regional chemistry transport model

    Science.gov (United States)

    Kuhlmann, G.; Lam, Y. F.; Cheung, H. M.; Hartl, A.; Fung, J. C. H.; Chan, P. W.; Wenig, M. O.

    2015-05-01

    In this paper, we present the custom Hong Kong NO2 retrieval (HKOMI) for the Ozone Monitoring Instrument (OMI) on board the Aura satellite which was used to evaluate a high-resolution chemistry transport model (CTM) (3 km x 3 km spatial resolution). The atmospheric chemistry transport was modelled in the Pearl River Delta (PRD) region in southern China by the Models-3 Community Multiscale Air Quality (CMAQ) modelling system from October 2006 to January 2007. In the HKOMI NO2 retrieval, tropospheric air mass factors (AMFs) were recalculated using high-resolution ancillary parameters of surface reflectance, a priori NO2 and aerosol profiles, of which the latter two were taken from the CMAQ simulation. We tested the influence of the ancillary parameters on the data product using four different aerosol parametrizations. Ground-level measurements by the PRD Regional Air Quality Monitoring (RAQM) network were used as additional independent measurements. The HKOMI retrieval increases estimated tropospheric NO2 vertical column densities (VCD) by (+31 ± 38)%, when compared to NASA's standard product (OMNO2-SP), and improves the normalized mean bias (NMB) between satellite and ground observations by 26 percentage points from -41 to -15%. The individual influences of the parameters are (+11.4 ± 13.4)% for NO2 profiles, (+11.0 ± 20.9)% for surface reflectance and (+6.0 ± 8.4)% for the best aerosol parametrization. The correlation coefficient r is low between ground and satellite observations (r = 0.35). The low r and the remaining NMB can be explained by the low model performance and the expected differences when comparing point measurements with area-averaged satellite observations. The correlation between CMAQ and the RAQM network is low (r ~ 0.3) and the model underestimates the NO2 concentrations in the northwestern model domain (Foshan and Guangzhou). We compared the CMAQ NO2 time series of the two main plumes with our best OMI NO2 data set (HKOMI-4). The model

  19. Atom trap trace analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Z.-T.; Bailey, K.; Chen, C.-Y.; Du, X.; Li, Y.-M.; O' Connor, T. P.; Young, L.

    2000-05-25

    A new method of ultrasensitive trace-isotope analysis has been developed based upon the technique of laser manipulation of neutral atoms. It has been used to count individual {sup 85}Kr and {sup 81}Kr atoms present in a natural krypton sample with isotopic abundances in the range of 10{sup {minus}11} and 10{sup {minus}13}, respectively. The atom counts are free of contamination from other isotopes, elements,or molecules. The method is applicable to other trace-isotopes that can be efficiently captured with a magneto-optical trap, and has a broad range of potential applications.

  20. Biases in Long-term NO2 Averages Inferred from Satellite Observations Due to Cloud Selection Criteria

    Science.gov (United States)

    Geddes, Jeffrey A.; Murphy, Jennifer G.; O'Brien, Jason M.; Celarier, Edward A.

    2012-01-01

    Retrievals of atmospheric trace gas column densities from space are compromised by the presence of clouds, requiring most studies to exclude observations with significant cloud fractions in the instrument's field of view. Using NO2 observations at three ground stations representing urban, suburban, and rural environments, and tropospheric vertical column densities measured by the Ozone Monitoring Instrument (OMI) over each site, we show that the observations from space represent monthly averaged ground-level pollutant conditions well (R=0.86) under relatively cloud-free conditions. However, by analyzing the ground-level data and applying the OMI cloud fraction as a filter, we show there is a significant bias in long-term averaged NO2 as a result of removing the data during cloudy conditions. For the ground-based sites considered in this study, excluding observations on days when OMI-derived cloud fractions were greater than 0.2 causes 12:00-14:00 mean summer mixing ratios to be underestimated by 12%+/-6%, 20%+/-7%, and 40%+/-10% on average (+/-1 standard deviation) at the urban, suburban, and rural sites respectively. This bias was investigated in particular at the rural site, a region where pollutant transport is the main source of NO2, and where longterm observations of NOy were also available. Evidence of changing photochemical conditions and a correlation between clear skies and the transport of cleaner air masses play key roles in explaining the bias. The magnitude of a bias is expected to vary from site to site depending on meteorology and proximity to NOx sources, and decreases when longer averaging times of ground station data (e.g. 24-h) are used for the comparison.

  1. In-situ NO and NO2 profiles measured onboard passenger aircraft over Frankfurt airport in Germany

    Science.gov (United States)

    Berkes, Florian; Houben, Norbert; Blomel, Torben; Tappertzhofen, Marlon; Volz-Thomas, Andreas; Petzold, Andreas

    2017-04-01

    NOx (sum of NO and NO2) play a central role in atmospheric chemistry related to ozone and oxidation capacity (OH and NO3 radicals). The most important sources of NOx in the upper troposphere are lightning, and transport from the boundary layer (combustion processes, from biomass burning, agriculture, and industry/transport/aircraft emissions). In-situ measurements of NOx from the upper troposphere and lower stratosphere (UTLS) down to the surface are rare, but important for understanding the local photochemistry and for the assessment of the impact of aviation on the budgets of greenhouse gases such as ozone. The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System) operates a global-scale monitoring system for atmospheric temperature, trace gases, aerosols and clouds at high spatial resolution by passenger aircraft. The IAGOS NOx instrument is designed for the autonomous measurement of nitrogen oxides over serval months. The measurement principle is based on the well-established chemiluminescence technique, using one channel with sequential measurements of NO and NOx every 50 s. Here, we present vertical profiles of nitrogen oxides from the UTLS down to the surface for day and night time conditions obtained over 12 months in 2015 and 2016. The analysis focuses mainly on Europe, the region with the largest amount of profiles. Other regions (North America, South America and East Asia) will also be discussed. Typically, NO and NO2 varies in the low ppt range in the UT, slightly increasing towards the pressure altitude of 200 hPa. Down to the surface, the values of NO and of NO2 increase up to several ppb. These profiles combined with in-situ water vapor and cloud parameters will be valuable for validation of model and of satellite data in the future.

  2. Lower vehicular primary emissions of NO2 in Europe than assumed in policy projections

    Science.gov (United States)

    Grange, Stuart K.; Lewis, Alastair C.; Moller, Sarah J.; Carslaw, David C.

    2017-12-01

    Many European countries do not meet legal air quality standards for ambient nitrogen dioxide (NO2) near roads; a problem that has been forecasted to persist to 2030. Although European air quality standards regulate NO2 concentrations, emissions standards for new vehicles instead set limits for NOx—the combination of nitric oxide (NO) and NO2. From around 1990 onwards, the total emissions of NOx declined significantly in Europe, but roadside concentrations of NO2—a regulated species—declined much less than expected. This discrepancy has been attributed largely to the increasing usage of diesel vehicles in Europe and more directly emitted tailpipe NO2. Here we apply a data-filtering technique to 130 million hourly measurements of NOx, NO2 and ozone (O3) from roadside monitoring stations across 61 urban areas in Europe over the period 1990-2015 to estimate the continent-wide trends of directly emitted NO2. We find that the ratio of NO2 to NOx emissions increased from 1995 to around 2010 but has since stabilized at a level that is substantially lower than is assumed in some key emissions inventories. The proportion of NOx now being emitted directly from road transport as NO2 is up to a factor of two smaller than the estimates used in policy projections. We therefore conclude that there may be a faster attainment of roadside NO2 air quality standards across Europe than is currently expected.

  3. Evaluation of a regional air quality forecast model for tropospheric NO2 columns using the OMI/Aura satellite tropospheric NO2 product

    Directory of Open Access Journals (Sweden)

    J. K. Vaughan

    2010-09-01

    Full Text Available Results from a regional air quality forecast model, AIRPACT-3, are compared to OMI tropospheric NO2 integrated column densities for an 18 month period over the Pacific Northwest. AIRPACT column densities are well correlated (r=0.75 to cloud-free (2 for monthly averages without wildfires, but are poorly correlated (r=0.21 with significant model over-predictions for months with wildfires when OMI and AIRPACT are compared over the entire domain. AIRPACT predicts higher NO2 in some northwestern US urban areas, and lower NO2 in the Vancouver, BC urban area, when compared to OMI. Model results are spatially averaged to the daily OMI swath. The Dutch KNMI (DOMINO and NASA (Standard Product retrievals of tropospheric NO2 from OMI (Collection-3 are compared. The NASA product is shown to be significantly different than the KNMI tropospheric NO2 product. The average difference in tropospheric columns, after applying the averaging kernels of the respective products to the model results, is shown to be larger in the summer (±50% than winter (±20%.

  4. TRACING CULPABLE IGNORANCE

    NARCIS (Netherlands)

    Peels, Rik

    2011-01-01

    In this paper, I respond to the following argument which several authors have presented. If we are culpable for some action, we act either from akrasia or from culpable ignorance. However, akrasia is highly exceptional and it turns out that tracing culpable ignorance leads to a vicious regress.

  5. Third order trace formula

    Indian Academy of Sciences (India)

    adjoint operator is bounded and the perturbation is ... Keywords. Trace formula; spectral shift function; perturbations of self-adjoint operators. 1. Introduction. Notations. .... j=1 j−1. ∑ k=0. Ar− j−1. Y(A + X)k X Aj−k−1, leading to the estimate. ∥. ∥.

  6. Third order trace formula

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 123; Issue 4. Third Order Trace Formula. Arup Chattopadhyay Kalyan B Sinha. Volume 123 Issue 4 November 2013 pp 547-575. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/pmsc/123/04/0547-0575 ...

  7. Phosphazene additives

    Science.gov (United States)

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  8. Epidemiology and trace elements.

    Science.gov (United States)

    Elwood, P C

    1985-08-01

    Basically, epidemiology is the making of measurements of known reproducibility, in a bias-free manner, on representative samples of subjects drawn from defined communities. Epidemiology has become a relatively precise science and its value in medicine is widely appreciated. So too are its limitations: the difficulties in achieving a high response rate, in identifying and controlling confounding factors in the examination of an association, and the ultimate difficulties in distinguishing causation from association. While the value of community-based studies seems to be recognized by those interested in man and his environment, the need for the strict application of epidemiological procedures, and the limitations imposed on conclusions drawn from studies in which these procedures have been compromised, does not seem to be adequately understood. There are certain known links between trace elements in the environment and disease: for example the level of iodine in soil and water and the prevalence of goitre; the level of fluoride in water and the prevalence of dental caries. The investigation of other possible associations is difficult for a number of reasons, including interrelationships between trace elements, confounding of trace element levels (and disease) with social and dietary factors, and the probability that relationships are generally weak. Two conditions in which associations are likely are cardiovascular disease and cancer. Despite research along a number of lines, the relevance of trace elements to cardiovascular disease is not clear, and certainly the apparent association with hardness of domestic water supply seems unlikely to be causal. The same general conclusion seems reasonable for cancer, and although there are a very few well established associations which are likely to be causal, such as exposure to arsenic and skin cancer, the role of trace elements is obscure, and likely to be very small.

  9. Global Free-tropospheric NO2 Abundances Derived Using a Cloud Slicing Technique from AURA OMI

    Science.gov (United States)

    Choi, S.; Joiner, J.; Choi, Y.; Duncan, B.N.; Vasilkov, A.; Krotkov, N.; Bucsela, E.J.

    2014-01-01

    We derive free-tropospheric NO2 volume mixing ratios (VMRs) by applying a cloud-slicing technique to data from the Ozone Monitoring Instrument (OMI) on the Aura satellite. In the cloud-slicing approach, the slope of the above-cloud NO2 column versus the cloud scene pressure is proportional to the NO2 VMR. In this work, we use a sample of nearby OMI pixel data from a single orbit for the linear fit. The OMI data include cloud scene pressures from the rotational-Raman algorithm and above-cloud NO2 vertical column density (VCD) (defined as the NO2 column from the cloud scene pressure to the top of the atmosphere) from a differential optical absorption spectroscopy (DOAS) algorithm. We compare OMI-derived NO2 VMRs with in situ aircraft profiles measured during the NASA Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaign in 2006. The agreement is generally within the estimated uncertainties when appropriate data screening is applied. We then derive a global seasonal climatology of free-tropospheric NO2 VMR in cloudy conditions. Enhanced NO2 in the free troposphere commonly appears near polluted urban locations where NO2 produced in the boundary layer may be transported vertically out of the boundary layer and then horizontally away from the source. Signatures of lightning NO2 are also shown throughout low and middle latitude regions in summer months. A profile analysis of our cloud-slicing data indicates signatures of lightning-generated NO2 in the upper troposphere. Comparison of the climatology with simulations from the global modeling initiative (GMI) for cloudy conditions (cloud optical depth less than10) shows similarities in the spatial patterns of continental pollution outflow. However, there are also some differences in the seasonal variation of free-tropospheric NO2 VMRs near highly populated regions and in areas affected by lightning-generated NOx.

  10. 7 CFR 51.2732 - U.S. No. 2 Spanish.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. No. 2 Spanish. 51.2732 Section 51.2732... STANDARDS) United States Standards for Grades of Shelled Spanish Type Peanuts Grades § 51.2732 U.S. No. 2 Spanish. “U.S. No. 2 Spanish” consists of shelled Spanish type peanut kernels which may be split or broken...

  11. High NO2/NOx emissions downstream of the catalytic diesel particulate filter: An influencing factor study.

    Science.gov (United States)

    He, Chao; Li, Jiaqiang; Ma, Zhilei; Tan, Jianwei; Zhao, Longqing

    2015-09-01

    Diesel vehicles are responsible for most of the traffic-related nitrogen oxide (NOx) emissions, including nitric oxide (NO) and nitrogen dioxide (NO2). The use of after-treatment devices increases the risk of high NO2/NOx emissions from diesel engines. In order to investigate the factors influencing NO2/NOx emissions, an emission experiment was carried out on a high pressure common-rail, turbocharged diesel engine with a catalytic diesel particulate filter (CDPF). NO2 was measured by a non-dispersive ultraviolet analyzer with raw exhaust sampling. The experimental results show that the NO2/NOx ratios downstream of the CDPF range around 20%-83%, which are significantly higher than those upstream of the CDPF. The exhaust temperature is a decisive factor influencing the NO2/NOx emissions. The maximum NO2/NOx emission appears at the exhaust temperature of 350°C. The space velocity, engine-out PM/NOx ratio (mass based) and CO conversion ratio are secondary factors. At a constant exhaust temperature, the NO2/NOx emissions decreased with increasing space velocity and engine-out PM/NOx ratio. When the CO conversion ratios range from 80% to 90%, the NO2/NOx emissions remain at a high level. Copyright © 2015. Published by Elsevier B.V.

  12. Comparison of tropospheric NO2 observations by GOME and ground stations over Tokyo, Japan

    Science.gov (United States)

    Noguchi, K.; Itoh, H.; Shibasaki, T.; Hayashida, S.; Uno, I.; Ohara, T.; Richter, A.; Burrows, J. P.

    2009-04-01

    Nitrogen oxides (NOx = NO + NO2) are anthropogenically emitted as a form of NO in the high-temperature burning processes of fossil fuels mainly in energy generations and vehicles. Because NOx is a precursor of ozone, which is composed of a so-called photochemical smog, and is a health-hazard matter, the monitoring of NO2 is important to control air quality. The satellite observation is one of the most suitable methods for the monitoring of air pollution because satellite observations can obtain a global distribution of the pollutants. However, the observation of tropospheric gases by satellites still includes technically challenging problems, and the field is developing. To test whether satellite observations could successfully detect the behavior of tropospheric NO2, we compared satellite and ground-based observations of tropospheric NO2 over the Tokyo region. The satellite data were tropospheric NO2 vertical column density (VCD) derived from Global Ozone Monitoring Experiment (GOME) spectrometer measurements (hereafter GOME-NO2) [Richter et al., 2005], and the ground-based data were surface NO2 volume mixing ratio (VMR) observed by the network of air-quality monitoring stations in Tokyo. The analysis was performed for the data from January 1996 to June 2003. We found a strong correlation between GOME-NO2 and the surface VMR. They showed a similar seasonal variation with a maximum in winter and a minimum in summer. The result suggested that GOME was observing the behavior of NO2 near the surface in the Tokyo region. A more rigorous comparison was conducted by scaling the surface NO2 VMR to the tropospheric VCD with vertical NO2 VMR profiles. The NO2 profiles were calculated by using the chemical transport model CMAQ/REAS [Uno et al., 2007; Ohara et al., 2007]. This second comparison indicated that the GOME observations represent the behavior of NO2 more closely at the relatively unpolluted ground stations than at the highly polluted ground stations of the air

  13. Automated computer analysis of plasma-streak traces from SCYLLAC

    International Nuclear Information System (INIS)

    Whiteman, R.L.; Jahoda, F.C.; Kruger, R.P.

    1977-11-01

    An automated computer analysis technique that locates and references the approximate centroid of single- or dual-streak traces from the Los Alamos Scientific Laboratory SCYLLAC facility is described. The technique also determines the plasma-trace width over a limited self-adjusting region. The plasma traces are recorded with streak cameras on Polaroid film, then scanned and digitized for processing. The analysis technique uses scene segmentation to separate the plasma trace from a reference fiducial trace. The technique employs two methods of peak detection; one for the plasma trace and one for the fiducial trace. The width is obtained using an edge-detection, or slope, method. Timing data are derived from the intensity modulation of the fiducial trace. To smooth (despike) the output graphs showing the plasma-trace centroid and width, a technique of ''twicing'' developed by Tukey was employed. In addition, an interactive sorting algorithm allows retrieval of the centroid, width, and fiducial data from any test shot plasma for post analysis. As yet, only a limited set of the plasma traces has been processed with this technique

  14. Automated computer analysis of plasma-streak traces from SCYLLAC

    International Nuclear Information System (INIS)

    Whitman, R.L.; Jahoda, F.C.; Kruger, R.P.

    1977-01-01

    An automated computer analysis technique that locates and references the approximate centroid of single- or dual-streak traces from the Los Alamos Scientific Laboratory SCYLLAC facility is described. The technique also determines the plasma-trace width over a limited self-adjusting region. The plasma traces are recorded with streak cameras on Polaroid film, then scanned and digitized for processing. The analysis technique uses scene segmentation to separate the plasma trace from a reference fiducial trace. The technique employs two methods of peak detection; one for the plasma trace and one for the fiducial trace. The width is obtained using an edge-detection, or slope, method. Timing data are derived from the intensity modulation of the fiducial trace. To smooth (despike) the output graphs showing the plasma-trace centroid and width, a technique of ''twicing'' developed by Tukey was employed. In addition, an interactive sorting algorithm allows retrieval of the centroid, width, and fiducial data from any test shot plasma for post analysis. As yet, only a limited set of sixteen plasma traces has been processed using this technique

  15. Pajanan NO2 Bulan Pertama dan Kedua Kehamilan terhadap Bayi dengan Berat Badan Lahir Rendah

    Directory of Open Access Journals (Sweden)

    Bunga Oktora

    2014-01-01

    Full Text Available Pajanan pencemar udara selama kehamilan berhubungan dengan bayi berat badan lahir rendah (BBLR. Untuk menghubungkan konsentrasi NO2 dalam udara ambien, telah dilakukan studi ekologi di Jakarta. Konsentrasi NO2 didapat dari data monitoring BPLHD DKI Jakarta 2009 – 2011, sedangkan kasus-kasus bayi BBLR diperoleh dari Dinas Kesehatan Provinsi DKI Jakarta. Data dianalisis dengan Anova, uji korelasi, dan regresi linier dan berganda. Hasil analisis menunjukkan bahwa konsentrasi NO2 dalam bulan pertama dan kedua kehamilan berhubungan bermakna dengan BBLR (masing-masing dengan R = 0,464, nilai p = 0,0001 dan R = 0,243, nilai p = 0,013. Regresi linier berganda menunjukkan bahwa konsentrasi NO2 dapat meramalkan 25% kasus BBLR (R = 0,5; R2 = 0,25; nilai p = 0,0001. Variabel yang paling memengaruhi BBLR adalah pajanan terhadap NO2 pada bulan pertama gestasi (B = 259. Disimpulkan, pajanan NO2 pada bulan pertama dan kedua kehamilan dan tempat wilayah tinggal berhubungan dengan BBLR, dengan pajanan NO2 pada bulan pertama kehamilan merupakan faktor utama BBLR. It has been known that exposure to air pollutant during pregnancy was associated with low birth weight. To correlate NO2 concentration in ambient air with baby with low birth weight (LBW, an ecological study has been carried in Jakarta. NO2 concentration was obtained from 2009 – 2011 monitoring data (Jakarta BPLHD, while low birth weight data were obtained from Jakarta Provincial Health Office. Anova, correlation, linear and multiple linear regressions were employed to analyze NO2 concentration with LBW. It showed that NO2 concentrations during first and second month of pregnancy were significantly correlated with the LBW (R = 0.464, p value = 0.0001 and R = 0.243, p value = 0.013. Multiple linear regression showed that the concentration of NO2 in the first and second month of pregnancy can predict 25% of LBW cases (R = 0.5, R2 = 0.25; p value = 0.0001. The most influence variable on LBW is exposure

  16. Quantification of the effect of modeled lightning NO2 on UV–visible air mass factors

    Directory of Open Access Journals (Sweden)

    J. L. Laughner

    2017-11-01

    Full Text Available Space-borne measurements of tropospheric nitrogen dioxide (NO2 columns are up to 10x more sensitive to upper tropospheric (UT NO2 than near-surface NO2 over low-reflectivity surfaces. Here, we quantify the effect of adding simulated lightning NO2 to the a priori profiles for NO2 observations from the Ozone Monitoring Instrument (OMI using modeled NO2 profiles from the Weather Research and Forecasting–Chemistry (WRF-Chem model. With observed NO2 profiles from the Deep Convective Clouds and Chemistry (DC3 aircraft campaign as observational truth, we quantify the bias in the NO2 column that occurs when lightning NO2 is not accounted for in the a priori profiles. Focusing on late spring and early summer in the central and eastern United States, we find that a simulation without lightning NO2 underestimates the air mass factor (AMF by 25 % on average for common summer OMI viewing geometry and 35 % for viewing geometries that will be encountered by geostationary satellites. Using a simulation with 500 to 665 mol NO flash−1 produces good agreement with observed NO2 profiles and reduces the bias in the AMF to  <  ±4 % for OMI viewing geometries. The bias is regionally dependent, with the strongest effects in the southeast United States (up to 80 % and negligible effects in the central US. We also find that constraining WRF meteorology to a reanalysis dataset reduces lightning flash counts by a factor of 2 compared to an unconstrained run, most likely due to changes in the simulated water vapor profile.

  17. Scaling relationship for NO2 pollution and urban population size: a satellite perspective.

    Science.gov (United States)

    Lamsal, L N; Martin, R V; Parrish, D D; Krotkov, N A

    2013-07-16

    Concern is growing about the effects of urbanization on air pollution and health. Nitrogen dioxide (NO2) released primarily from combustion processes, such as traffic, is a short-lived atmospheric pollutant that serves as an air-quality indicator and is itself a health concern. We derive a global distribution of ground-level NO2 concentrations from tropospheric NO2 columns retrieved from the Ozone Monitoring Instrument (OMI). Local scaling factors from a three-dimensional chemistry-transport model (GEOS-Chem) are used to relate the OMI NO2 columns to ground-level concentrations. The OMI-derived surface NO2 data are significantly correlated (r = 0.69) with in situ surface measurements. We examine how the OMI-derived ground-level NO2 concentrations, OMI NO2 columns, and bottom-up NOx emission inventories relate to urban population. Emission hot spots, such as power plants, are excluded to focus on urban relationships. The correlation of surface NO2 with population is significant for the three countries and one continent examined here: United States (r = 0.71), Europe (r = 0.67), China (r = 0.69), and India (r = 0.59). Urban NO2 pollution, like other urban properties, is a power law scaling function of the population size: NO2 concentration increases proportional to population raised to an exponent. The value of the exponent varies by region from 0.36 for India to 0.66 for China, reflecting regional differences in industrial development and per capita emissions. It has been generally established that energy efficiency increases and, therefore, per capita NOx emissions decrease with urban population; here, we show how outdoor ambient NO2 concentrations depend upon urban population in different global regions.

  18. Validation of ACE and OSIRIS ozone and NO2 measurements using ground-based instruments at 80° N

    Directory of Open Access Journals (Sweden)

    A. Pazmino

    2012-05-01

    with the ground-based ozone total columns with mean relative differences of 0.1–7.3%. For NO2, partial columns from 17 km upward were scaled to noon using a photochemical model. Mean relative differences between OSIRIS, ACE-FTS and ground-based NO2 measurements do not exceed 20%. ACE-MAESTRO measures more NO2 than the other instruments, with mean relative differences of 25–52%. Seasonal variation in the differences between NO2 partial columns is observed, suggesting that there are systematic errors in the measurements and/or the photochemical model corrections. For ozone spring-time measurements, additional coincidence criteria based on stratospheric temperature and the location of the polar vortex were found to improve agreement between some of the instruments. For ACE-FTS v2.2 minus Bruker FTIR, the 2007–2009 spring-time mean relative difference improved from −5.0 ± 0.4% to −3.1 ± 0.8% with the dynamical selection criteria. This was the largest improvement, likely because both instruments measure direct sunlight and therefore have well-characterized lines-of-sight compared with scattered sunlight measurements. For NO2, the addition of a ±1° latitude coincidence criterion improved spring-time intercomparison results, likely due to the sharp latitudinal gradient of NO2 during polar sunrise. The differences between satellite and ground-based measurements do not show any obvious trends over the missions, indicating that both the ACE and OSIRIS instruments continue to perform well.

  19. Singular traces theory and applications

    CERN Document Server

    Sukochev, Fedor; Zanin, Dmitriy

    2012-01-01

    This text is the first complete study and monograph dedicated to singular traces. For mathematical readers the text offers, due to Nigel Kalton's contribution, a complete theory of traces on symmetrically normed ideals of compact operators. For mathematical physicists and other users of Connes' noncommutative geometry the text offers a complete reference to Dixmier traces and the deeper mathematical features of singular traces. An application section explores the consequences of these features, which previously were not discussed in general texts on noncommutative geometry.

  20. Novel Base Metal-Palladium Catalytic Diesel Filter Coating with NO2 Reducing Properties

    DEFF Research Database (Denmark)

    Johansen, K.; Dahl, S.; Mogensen, G.

    2007-01-01

    A novel alternative base metal/palladium coat has been developed that has limited NO2 formation and which even removes NO2 in a wide temperature range.Soot combustion, HC conversion and CO conversion properties are comparable to current platinum based solutions but the coating has a more attracti...

  1. Observation of slant column NO2 using the super-zoom mode of AURA-OMI

    NARCIS (Netherlands)

    Valin, L.C.; Russell, A.R.; Bucsela, E.J.; Veefkind, J.P.; Cohen, R.C.

    2011-01-01

    We retrieve slant column NO2 from the superzoom mode of the Ozone Monitoring Instrument (OMI) to explore its utility for understanding NOx emissions and variability. Slant column NO2 is operationally retrieved from OMI (Boersma et al., 2007; Bucsela et al., 2006) with a nadir footprint of 13×24 km2,

  2. NO2 gas sorption studies of Ge33Se67 films using quartz crystal microbalance

    International Nuclear Information System (INIS)

    Georgieva, Velichka; Mitkova, Maria; Chen, Ping; Tenne, Dmitri; Wolf, Kasandra; Gadjanova, Victoria

    2012-01-01

    A study on the NO 2 gas sorption ability of amorphous Ge 33 Se 67 coated quartz crystal microbalance (QCM) is presented. The thin films have been characterized before and after sorption/desorption processes of NO 2 by energy-dispersive X-ray spectroscopy (EDS), grazing angle X-ray diffraction (GAXRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and atom force microscopy (AFM) measurements. These studies indicated that physisorption occurs when NO 2 gas molecules are introduced into the chalcogenide film and the thin film composition or structure do not change. The mass loading due to NO 2 gas sorption was calculated by the resonator’s frequency shift. At the conditions of our experiment, up to 6.8 ng of the gas was sorbed into 200 nm thick Ge 33 Se 67 film at 5000 ppm NO 2 concentration. It has been established that the process of gas molecules sorption is reversible. Highlights: ► Ge 33 Se 67 thin film and quartz crystal microbalance for NO 2 gas sensing. ► Physisorption of NO 2 in Ge 33 Se 67 thin films. ► Reversibility of the NO 2 sorption in Ge 33 Se 67 thin films. ► Pure physical effect of gas sorption revealed by Raman, XPS, AFM. ► Large free volume of the thin films encountered through GAXRD.

  3. Tracing Actual Causes

    Science.gov (United States)

    2016-08-08

    was articu- lated by David Lewis in his work on causal ex- planations [Lewis, 1986a]. We address the prob- lem by defining the causal history of the...of actual causation involve coun- terfactuals. The counterfactual tradition goes back to Hume [ Hume , 1748] whose position was that an event c is a...work We present a new take on the old problem of tracing ac- tual causes articulated by David Lewis in his work on causal explanations [Lewis, 1986a]. We

  4. Trace elements in adolescents

    OpenAIRE

    Barany, Ebba

    2002-01-01

    The major aim of the thesis was to monitor toxic and essential trace elements in a cohort of adolescents by blood and serum analyses, and describe the impact of different factors on the element concentrations. The adolescents were from the Swedish cities Uppsala and Trollhättan which represent different socioeconomic and environmental conditions, and were investigated at age 15 and 17. It was shown that an inductively coupled plasma mass spectrometry method was suitable for simultaneous deter...

  5. On Trace Zero Matrices

    Indian Academy of Sciences (India)

    In this note, we shall try to present an elemen- tary proof of a couple of closely related results which have both proved quite useful, and al~ indicate possible generalisations. The results we have in mind are the following facts: (a) A complex n x n matrix A has trace 0 if and only if it is expressible in the form A = PQ - Q P.

  6. Anisotropic ray trace

    Science.gov (United States)

    Lam, Wai Sze Tiffany

    Optical components made of anisotropic materials, such as crystal polarizers and crystal waveplates, are widely used in many complex optical system, such as display systems, microlithography, biomedical imaging and many other optical systems, and induce more complex aberrations than optical components made of isotropic materials. The goal of this dissertation is to accurately simulate the performance of optical systems with anisotropic materials using polarization ray trace. This work extends the polarization ray tracing calculus to incorporate ray tracing through anisotropic materials, including uniaxial, biaxial and optically active materials. The 3D polarization ray tracing calculus is an invaluable tool for analyzing polarization properties of an optical system. The 3x3 polarization ray tracing P matrix developed for anisotropic ray trace assists tracking the 3D polarization transformations along a ray path with series of surfaces in an optical system. To better represent the anisotropic light-matter interactions, the definition of the P matrix is generalized to incorporate not only the polarization change at a refraction/reflection interface, but also the induced optical phase accumulation as light propagates through the anisotropic medium. This enables realistic modeling of crystalline polarization elements, such as crystal waveplates and crystal polarizers. The wavefront and polarization aberrations of these anisotropic components are more complex than those of isotropic optical components and can be evaluated from the resultant P matrix for each eigen-wavefront as well as for the overall image. One incident ray refracting or reflecting into an anisotropic medium produces two eigenpolarizations or eigenmodes propagating in different directions. The associated ray parameters of these modes necessary for the anisotropic ray trace are described in Chapter 2. The algorithms to calculate the P matrix from these ray parameters are described in Chapter 3 for

  7. Tracers and tracing methods

    International Nuclear Information System (INIS)

    Leclerc, J.P.

    2001-01-01

    The first international congress on 'Tracers and tracing methods' took place in Nancy in May 2001. The objective of this second congress was to present the current status and trends on tracing methods and their applications. It has given the opportunity to people from different fields to exchange scientific information and knowledge about tracer methodologies and applications. The target participants were the researchers, engineers and technologists of various industrial and research sectors: chemical engineering, environment, food engineering, bio-engineering, geology, hydrology, civil engineering, iron and steel production... Two sessions have been planned to cover both fundamental and industrial aspects: 1)fundamental development (tomography, tracer camera visualization and particles tracking; validation of computational fluid dynamics simulations by tracer experiments and numerical residence time distribution; new tracers and detectors or improvement and development of existing tracing methods; data treatments and modeling; reactive tracer experiments and interpretation) 2)industrial applications (geology, hydrogeology and oil field applications; civil engineering, mineral engineering and metallurgy applications; chemical engineering; environment; food engineering and bio-engineering). The program included 5 plenary lectures, 23 oral communications and around 50 posters. Only 9 presentations are interested for the INIS database

  8. A high-resolution and observationally constrained OMI NO2 satellite retrieval

    Science.gov (United States)

    Goldberg, Daniel L.; Lamsal, Lok N.; Loughner, Christopher P.; Swartz, William H.; Lu, Zifeng; Streets, David G.

    2017-09-01

    This work presents a new high-resolution NO2 dataset derived from the NASA Ozone Monitoring Instrument (OMI) NO2 version 3.0 retrieval that can be used to estimate surface-level concentrations. The standard NASA product uses NO2 vertical profile shape factors from a 1.25° × 1° (˜ 110 km × 110 km) resolution Global Model Initiative (GMI) model simulation to calculate air mass factors, a critical value used to determine observed tropospheric NO2 vertical columns. To better estimate vertical profile shape factors, we use a high-resolution (1.33 km × 1.33 km) Community Multi-scale Air Quality (CMAQ) model simulation constrained by in situ aircraft observations to recalculate tropospheric air mass factors and tropospheric NO2 vertical columns during summertime in the eastern US. In this new product, OMI NO2 tropospheric columns increase by up to 160 % in city centers and decrease by 20-50 % in the rural areas outside of urban areas when compared to the operational NASA product. Our new product shows much better agreement with the Pandora NO2 and Airborne Compact Atmospheric Mapper (ACAM) NO2 spectrometer measurements acquired during the DISCOVER-AQ Maryland field campaign. Furthermore, the correlation between our satellite product and EPA NO2 monitors in urban areas has improved dramatically: r2 = 0.60 in the new product vs. r2 = 0.39 in the operational product, signifying that this new product is a better indicator of surface concentrations than the operational product. Our work emphasizes the need to use both high-resolution and high-fidelity models in order to recalculate satellite data in areas with large spatial heterogeneities in NOx emissions. Although the current work is focused on the eastern US, the methodology developed in this work can be applied to other world regions to produce high-quality region-specific NO2 satellite retrievals.

  9. Evaluating data for atmospheric models, an example: IO + NO2 = IONO2.

    Science.gov (United States)

    Golden, David M

    2006-03-09

    Data for the title reaction have been fit to the different formalisms used by the NASA and IUPAC data evaluation panels. The data are well represented by either formalism. Reported values for the bond dissociation energy at 0 K, D0(IO-NO2) vary from about 95 to 135 kJ mol(-1), with uncertainty ranges of about 20 kJ mol(-1). Master equation/RRKM methods were employed in an attempt to reconcile these values with the data. This was possible within reasonable bounds and suggests a value in the neighborhood of 150 kJ mol(-1). As always, there are sufficient assumptions and unknowns in such an attempt, that this value is somewhat uncertain, but the true value is not expected to be too far from this result. Thus, it is possible to evaluate data of the type addressed here in a manner reasonably consistent with the basic understanding of pressure dependent rate coefficients for use in atmospheric or other models of "engineering" problems. There are, however, strict limits on our ability to know specific details. It is possible that true anharmonicity corrections that include stretch-bend interactions as well as effects due to averaging rotational contributions could combine to lower this value by as much as 10 kJ mol(-1). In addition collision and energy transfer parameters are somewhat uncertain.

  10. Sensitive Multi-Species Emissions Monitoring: Infrared Laser-Based Detection of Trace-Level Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Steill, Jeffrey D. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Huang, Haifeng [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hoops, Alexandra A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Patterson, Brian D. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Birtola, Salvatore R. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Jaska, Mark [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Strecker, Kevin E. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Chandler, David W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bisson, Soott [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2014-09-01

    This report summarizes our development of spectroscopic chemical analysis techniques and spectral modeling for trace-gas measurements of highly-regulated low-concentration species present in flue gas emissions from utility coal boilers such as HCl under conditions of high humidity. Detailed spectral modeling of the spectroscopy of HCl and other important combustion and atmospheric species such as H 2 O, CO 2 , N 2 O, NO 2 , SO 2 , and CH 4 demonstrates that IR-laser spectroscopy is a sensitive multi-component analysis strategy. Experimental measurements from techniques based on IR laser spectroscopy are presented that demonstrate sub-ppm sensitivity levels to these species. Photoacoustic infrared spectroscopy is used to detect and quantify HCl at ppm levels with extremely high signal-to-noise even under conditions of high relative humidity. Additionally, cavity ring-down IR spectroscopy is used to achieve an extremely high sensitivity to combustion trace gases in this spectral region; ppm level CH 4 is one demonstrated example. The importance of spectral resolution in the sensitivity of a trace-gas measurement is examined by spectral modeling in the mid- and near-IR, and efforts to improve measurement resolution through novel instrument development are described. While previous project reports focused on benefits and complexities of the dual-etalon cavity ring-down infrared spectrometer, here details on steps taken to implement this unique and potentially revolutionary instrument are described. This report also illustrates and critiques the general strategy of IR- laser photodetection of trace gases leading to the conclusion that mid-IR laser spectroscopy techniques provide a promising basis for further instrument development and implementation that will enable cost-effective sensitive detection of multiple key contaminant species simultaneously.

  11. Bayero Journal of Pure and Applied Sciences - Vol 4, No 2 (2011)

    African Journals Online (AJOL)

    Trace Elements as Indicators of Quality of Drinking Water in Offa Metropolis, Kwara State, Nigeria · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. WLO Jimoh, QO Sholadoye, 103-108 ...

  12. South African Journal of Higher Education - Vol 15, No 2 (2001)

    African Journals Online (AJOL)

    Understanding co-operative learning: a case study in tracing relationships to social constructivism and South African socio-educational thought · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. E Bitzer, 98-104 ...

  13. Interferences in photolytic NO2 measurements: explanation for an apparent missing oxidant?

    Directory of Open Access Journals (Sweden)

    C. Reed

    2016-04-01

    Full Text Available Measurement of NO2 at low concentrations (tens of ppts is non-trivial. A variety of techniques exist, with the conversion of NO2 into NO followed by chemiluminescent detection of NO being prevalent. Historically this conversion has used a catalytic approach (molybdenum; however, this has been plagued with interferences. More recently, photolytic conversion based on UV-LED irradiation of a reaction cell has been used. Although this appears to be robust there have been a range of observations in low-NOx environments which have measured higher NO2 concentrations than might be expected from steady-state analysis of simultaneously measured NO, O3, jNO2, etc. A range of explanations exist in the literature, most of which focus on an unknown and unmeasured “compound X” that is able to convert NO to NO2 selectively. Here we explore in the laboratory the interference on the photolytic NO2 measurements from the thermal decomposition of peroxyacetyl nitrate (PAN within the photolysis cell. We find that approximately 5 % of the PAN decomposes within the instrument, providing a potentially significant interference. We parameterize the decomposition in terms of the temperature of the light source, the ambient temperature, and a mixing timescale ( ∼ 0.4 s for our instrument and expand the parametric analysis to other atmospheric compounds that decompose readily to NO2 (HO2NO2, N2O5, CH3O2NO2, IONO2, BrONO2, higher PANs. We apply these parameters to the output of a global atmospheric model (GEOS-Chem to investigate the global impact of this interference on (1 the NO2 measurements and (2 the NO2 : NO ratio, i.e. the Leighton relationship. We find that there are significant interferences in cold regions with low NOx concentrations such as the Antarctic, the remote Southern Hemisphere, and the upper troposphere. Although this interference is likely instrument-specific, the thermal decomposition to NO2 within the instrument's photolysis

  14. Thermal conductivity of molten KNO3-NaNO2 mixtures measured with wave-front shearing interferometry

    International Nuclear Information System (INIS)

    Iwadate, Yasuhiko; Kawamura, Kazutaka; Okada, Isao.

    1982-01-01

    The thermal conductivities are estimated from data obtained by wave-front shearing interferomety using available data on the density and the heat capacity. The thermal diffusivities and the thermal conductivities of molten KNO 3 -NaNO 2 mixtures increase and decrease slightly with a rise of temperature depending on the molar ratio of KNO 3 to NaNO 2 . They are expressed as linear functions of temperature as shown in Table 3. The results suggest that the ionic melts containing the ions of smaller mass have the larger thermal conductivities. The thermal conductivities of the mixture melts deviate negatively from the additivity. The validity of the proposed theories to the KNO 3 -NaNO 2 system has been studied in which the effects of mass, melting point, and density on thermal conductivity are taken into account. The formula of heat transfer proposed by Rao is best applicable to the thermal conductivity of the mixture. Our result is well expressed by the following formula, K = 2742.T sub(m)sup(1/2).rho sub(m)sup(2/3)/M sup(7/6), where K is the thermal conductivity, T sub(m) the molting point, rho sub(m) the density at T sub(m), and M the mean mass (averaged molecular weight), while the constant is 2742 instead of 2090 according to Rao. Whereas the thermal conductivity of pure alkali nitrate correlates linearly with the ultrasonic sound velocity, this relation does not hold in the molten KNO 3 -NaNO 2 mixture. The additivity rule can be applied to the sound velocity, but not to the thermal conductivity owing to its excess conductivity. (author)

  15. Mobile MAX-DOAS observation of NO2 and comparison with OMI satellite data in the western coastal areas of the Korean peninsula.

    Science.gov (United States)

    Chong, Jihyo; Kim, Young J; Gu, Myojeong; Wagner, Thomas; Song, Chul H

    2016-01-01

    Ground-based MAX-DOAS measurements have been used to retrieve column densities of atmospheric absorbers such as NO2, SO2, HCHO, and O3. In this study, mobile MAX-DOAS measurements were conducted to map the 2-D distributions of atmospheric NO2 in the western coastal areas of the Korean peninsula. A Mini-MAX-DOAS instrument was mounted on the rooftop of a mobile lab vehicle with a telescope mounted parallel to the driving direction, pointing forward. The measurements were conducted from 21 to 24 December 2010 along the western coastal areas from Gomso harbor (35.59N, 126.61E) to Gunsan harbor (35.98N, 126.67E). During mobile MAX-DOAS observations, high elevation angles were used to avoid shades from nearby obstacles. For the determination of the tropospheric vertical column density (VCD), the air mass factor (AMF) was retrieved by the so-called geometric approximation. The NO2 VCDs from 20 and 45 degree elevation angles were retrieved from mobile MAX-DOAS measurements. The tropospheric NO2 VCDs derived from mobile MAX-DOAS measurements were compared directly to those retrieved by the OMI satellite observations. Mobile MAX-DOAS VCD was in good agreement with OMI tropospheric VCD on most days. However, OMI tropospheric VCD was much higher than that of mobile MAX-DOAS on 23 December 2010. One probable reason for this difference is that OMI retrieval might overestimate NO2 VCD under haze conditions, when a pollution plume was transported over the measurement site. The mobile MAX-DOAS observations reveal much finer spatial patterns of NO2 distributions, which can provide useful information for the validation of satellite observation of atmospheric trace gases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Solvothermally synthesized tungsten oxide nanowires/nanorods for NO2 gas sensor applications

    International Nuclear Information System (INIS)

    Qin Yuxiang; Li Xiao; Wang Fei; Hu Ming

    2011-01-01

    Highlights: → Tungsten oxide nanowires and nanorods were solvothermally synthesized by changing reaction solvent. → The sensing characteristics of the tungsten oxide nanowires and nanorods sensors to NO 2 gas were evaluated in detail. → The response time and recovery time for the nanowires or nanorods sensors are much shorter than the oxide nanoparticles or sputtered films. → The nanowires sensor shows a much shorter response time and a relative higher response value to NO 2 gas than the nanorods one. → The NO 2 -sensing mechanism and the possible reason for the better gas sensing properties of the nanowires are analyzed. - Abstract: One-dimensional nanorods or nanowires of W 18 O 49 were synthesized by solvothermal method at 200 deg. C with tungsten hexachloride (WCl 6 ) as precursor and cyclohexanol or 1-propanol as reaction solvent. Their morphology and structure properties were systematically characterized. The NO 2 -sensing properties of the sensors based on nanowires and nanorods were investigated at 100 deg. C up to 250 deg. C over NO 2 concentration ranging from 1 ppm to 20 ppm. The results indicate that both nanowires and nanorods exhibit reversible response to different concentrations of NO 2 , and the highest gas response is achieved at 150 deg. C. In comparison with nanorods, nanowires showed a much quicker response characteristic and a relative higher response value to the same concentration of NO 2 gas due to the smaller diameter and larger specific surface area.

  17. National patterns in environmental injustice and inequality: outdoor NO2 air pollution in the United States.

    Science.gov (United States)

    Clark, Lara P; Millet, Dylan B; Marshall, Julian D

    2014-01-01

    We describe spatial patterns in environmental injustice and inequality for residential outdoor nitrogen dioxide (NO2) concentrations in the contiguous United States. Our approach employs Census demographic data and a recently published high-resolution dataset of outdoor NO2 concentrations. Nationally, population-weighted mean NO2 concentrations are 4.6 ppb (38%, penvironmental health implications of that concentration disparity are compelling. For example, we estimate that reducing nonwhites' NO2 concentrations to levels experienced by whites would reduce Ischemic Heart Disease (IHD) mortality by ∼7,000 deaths per year, which is equivalent to 16 million people increasing their physical activity level from inactive (0 hours/week of physical activity) to sufficiently active (>2.5 hours/week of physical activity). Inequality for NO2 concentration is greater than inequality for income (Atkinson Index: 0.11 versus 0.08). Low-income nonwhite young children and elderly people are disproportionately exposed to residential outdoor NO2. Our findings establish a national context for previous work that has documented air pollution environmental injustice and inequality within individual US metropolitan areas and regions. Results given here can aid policy-makers in identifying locations with high environmental injustice and inequality. For example, states with both high injustice and high inequality (top quintile) for outdoor residential NO2 include New York, Michigan, and Wisconsin.

  18. Validation of SCIAMACHY limb NO2 profiles using solar occultation measurements

    Directory of Open Access Journals (Sweden)

    H. Bovensmann

    2012-05-01

    Full Text Available The increasing amounts of reactive nitrogen in the stratosphere necessitate accurate global measurements of stratospheric nitrogen dioxide (NO2. Over the past decade, the SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY instrument on ENVISAT (European Environmental Satellite has been providing global coverage of stratospheric NO2 every 6 days. In this study, the vertical distributions of NO2 retrieved from SCIAMACHY limb measurements of the scattered solar light are validated by comparison with NO2 products from three different satellite instruments (SAGE II, HALOE and ACE-FTS. The retrieval algorithm based on the information operator approach is discussed, and the sensitivity of the SCIAMACHY NO2 limb retrievals is investigated. The photochemical corrections needed to make this validation feasible, and the chosen collocation criteria are described. For each instrument, a time period of two years is analyzed with several hundreds of collocation pairs for each year. As NO2 is highly variable, the comparisons are performed for five latitudinal bins and four seasons. In the 20 to 40 km altitude range, mean relative differences between SCIAMACHY and other instruments are found to be typically within 20 to 30%. The mean partial NO2 columns in this altitude range agree typically within 15% (both global monthly and zonal annual means. Larger differences are seen for SAGE II comparisons, which is consistent with the results presented by other authors. For SAGE II and ACE-FTS, the observed differences can be partially attributed to the diurnal effect error.

  19. Trace of Knowledge: Benchmarking Novel Text Mining Based Measurements

    DEFF Research Database (Denmark)

    Woltmann, Sabrina

    2018-01-01

    basic and more advanced statistical learning tools from the field of computational linguistics and statistical learning to trace the knowledge fragments[2, 6]. In addition, we utilize a mixture of standard algebraic and probabilistic methods. Furthermore, pattern recognition, classification algorithms...

  20. Re-evaluating the NO 2 hotspot over the South African Highveld

    Directory of Open Access Journals (Sweden)

    Alexandra S.M. Lourens

    2012-10-01

    Full Text Available Globally, numerous pollution hotspots have been identified using satellite-based instruments. One of these hotspots is the prominent NO2hotspot over the South African Highveld. The tropospheric NO2column density of this area is comparable to that observed for central and northern Europe, eastern North America and south-east Asia. The most well-known pollution source in this area is a large array of coal-fired power stations. Upon closer inspection, long-term means of satellite observations also show a smaller area, approximately 100 km west of the Highveld hotspot, with a seemingly less substantial NO2column density. This area correlates with the geographical location of the Johannesburg–Pretoria conurbation or megacity, one of the 40 largest metropolitan areas in the world. Ground-based measurements indicate that NO2concentrations in the megacity have diurnal peaks in the early morning and late afternoon, which coincide with peak traffic hours and domestic combustion. During these times, NO2concentrations in the megacity are higher than those in the Highveld hotspot. These diurnal NO2 peaks in the megacity have generally been overlooked by satellite observations because the satellites have fixed local overpass times that do not coincide with these peak periods. Consequently, the importance of NO2 over the megacity has been underestimated. We examined the diurnal cycles of NO2 ground-based measurements for the two areas – the megacity and the Highveld hotspot – and compared them with the satellite-based NO2 observations. Results show that the Highveld hotspot is accompanied by a second hotspot over the megacity, which is of significance for the more than 10 million people living in this megacity.

  1. Queer Tracings of Genre

    DEFF Research Database (Denmark)

    Balle, Søren Hattesen

    A prominent feature of John Ashbery's debut collection Some Trees is the near ubiquity of classical and post-classical genre designations attached as titles to its poems. Among them appear titles such as "Eclogue", "Sonnet", "Meditations of a Parrot", and "A Pastoral". Neither does Ashbery hesitate...... as (re)tracings of genres that appear somehow residual or defunct in a post-modernist poetic context. On the other, they are made to "encode new [and queer, shb] meanings" (Anne Ferry) inasmuch as Ashbery, for instance, doubles and literalizes Dante's false etymology of the word ‘eclogue' (aig- and logos...

  2. Osteoporosis and trace elements

    DEFF Research Database (Denmark)

    Aaseth, J.; Boivin, G.; Andersen, Ole

    2012-01-01

    More than 200 million people are affected by osteoporosis worldwide, as estimated by 2 million annual hip fractures and other debilitating bone fractures (vertebrae compression and Colles' fractures). Osteoporosis is a multi-factorial disease with potential contributions from genetic, endocrine...... in new bone and results in a net gain in bone mass, but may be associated with a tissue of poor quality. Aluminum induces impairment of bone formation. Gallium and cadmium suppresses bone turnover. However, exact involvements of the trace elements in osteoporosis have not yet been fully clarified...

  3. HIRDLS/Aura Level 3 Nitrogen Dioxide (NO2) Zonal Fourier Coefficients V007

    Data.gov (United States)

    National Aeronautics and Space Administration — The "HIRDLS/Aura Level 3 Nitrogen Dioxide (NO2) Zonal Fourier Coefficients" version 7 data product (H3ZFCNO2) contains the entire mission (~3 years) of HIRDLS data...

  4. Chopin: Concerto for piano and orchestra No. 2 in F minor / Christopher Headington

    Index Scriptorium Estoniae

    Headington, Christopher

    1992-01-01

    Uuest heliplaadist "Chopin: Concerto for piano and orchestra No. 2 in F minor, Op. 21; Schumann: Concerto for piano and orchestra in A minor Op. 54. Philharmonia Orchestra, Neeme Järvi". Chandos CHAN9061 (62 minutes:DDD)

  5. TES/Aura L2 NO2 Limb Special Observation V006

    Data.gov (United States)

    National Aeronautics and Space Administration — The TES Aura L2 NO2 data consist of information for one molecular species for an entire Global Survey or Special Observation. TES Level 2 data contain retrieved...

  6. Room temperature detection of NO2 using InSb nanowire

    Science.gov (United States)

    Paul, Rajat Kanti; Badhulika, Sushmee; Mulchandani, Ashok

    2011-07-01

    Room temperature detection of NO2 down to one part-per-million (ppm) using single crystalline n-type InSb nanowires (NWs) chemiresistive gas sensor is presented. These sensors were synthesized and fabricated by the combination of chemical vapor deposition and dielectrophoresis alignment techniques. The sensor devices showed an increase in resistance upon exposure to successive increments of NO2 concentration up to 10 ppm. The reduction in conductance of n-type InSb NWs when exposed to NO2 is made possible due to the charge transfer from the InSb NW surface to the adsorbed electron acceptor NO2 molecules. The demonstrated results suggest InSb NW as a promising candidate in sensing applications as well as being environmental friendly over existing arsenic and/or phosphorous-based III-V NW sensors.

  7. On the use of Satellite Remote Sensing and GIS to detect NO2 in the Troposphere

    DEFF Research Database (Denmark)

    Nielsen, Søren Zebitz

    2012-01-01

    This thesis studies the spatio-temporal patterns and trends in NO2 air pollution over Denmark using the satellite remote sensing product OMNO2e retrieved from the OMI instrument on the NASA AURA satellite. These data are related to in situ measurements of NO2 made at four rural and four urban...... are conducted, and it is shown that plumes from major Danish source areas can be detected in all wind directions, and that pollution transported from Europe is seen when the wind has a southern component. Examples of day to day tracking of transport of NO2 are also given to explain two pollution episodes...... measured in Denmark. Trends in the data are assessed and declining trends are seen over several European cities, whereas no significant trends are found in the Danish area. The mean distribution of NO2 from the satellite data is also used to evaluate the NOx emission inventory....

  8. 77 FR 9532 - Air Quality Designations for the 2010 Primary Nitrogen Dioxide (NO2

    Science.gov (United States)

    2012-02-17

    ...) 551-7606. Monica Morales, Leader, Air Quality Colorado, Montana, North Planning Unit, EPA Region 8... NAAQS and design values have not exceeded 42 percent of the 2010 NO 2 NAAQS. After considering state and...

  9. Testing of cavity attenuation phase shift technology for siting near-road NO2 monitors.

    Science.gov (United States)

    2015-07-01

    Recent research has identified the public health importance of air pollution exposures : near busy roadways. As a result, EPA significantly revised its NO2 air quality standard in 2010. : The current regulatory focus has shifted from assessment of lo...

  10. 2014-12-19_PASSIVE NO2 STUDY_final data_kovalcik.xlsx

    Data.gov (United States)

    U.S. Environmental Protection Agency — Nitrogen dioxide (NO2) concentrations relative to near road sites in Research Triangle area of North Carolina. This dataset is associated with the following...

  11. Satellite-Derived NO2 as an Indicator of Urban Air Quality and Emissions

    Science.gov (United States)

    Holloway, T.; Penn, E.; Harkey, M.

    2016-12-01

    Nitrogen dioxide (NO2) is the satellite-derived constituent with the most direct connection to fossil fuel emissions. At present the Ozone Monitoring Instrument aboard the NASA Aura satellite offers the highest resolution NO2retrievals, and new missions under development (TropOMI, TEMPO, GEMS, Sentinel-4) offer the potential for improved data in coming years. We present results applying satellite-derived NO2data to characterize air quality and emissions in U.S. cities. We highlight research findings geared toward increasing the relevance of satellite data to evaluate urban-scale air quality issues. This work reflects activities under the NASA Air Quality Applied Sciences Team (AQAST), and emerging work under the NASA Health and Air Quality Applied Sciences Team (H-AQAST). Among our results is a characterization of the diurnal cycle of nitrogen oxides using ground-based observations and satellite data. In situ monitoring from the U.S. EPA Air Quality System (AQS) shows that most locations have two daily peaks in NO2 (morning and evening) and a single daily peak in NO (morning). Spaced-based observations from the ESA Global Ozone Monitoring Experiment-2 (GOME-2), with a mid-morning overpass, and the NASA OMI, with an early afternoon overpass, support a complementary analysis for characterizing diurnal variability in NO2. Both ground-based monitors and satellite data show a reduction in the amplitude of the diurnal NO2 cycle. In the Western U.S., satellite data showed evidence of higher NO2 in urban centers in the afternoon (OMI) and higher NO2 in suburban areas in the morning (GOME-2), consistent with diurnal traffic patterns associated with commuting. Some power plants in the Western U.S. showed an increase in NO2in the afternoon, consistent with peak power demand associated with building air conditioning use. We extend this city-focused analysis satellite-derived HCHO:NO2 ratios as an indicator of ozone production regime, comparing modeled and measured ratios

  12. High-resolution mapping of the NO2 spatial distribution over Belgian urban areas based on airborne APEX remote sensing

    Science.gov (United States)

    Tack, Frederik; Merlaud, Alexis; Iordache, Marian-Daniel; Danckaert, Thomas; Yu, Huan; Fayt, Caroline; Meuleman, Koen; Deutsch, Felix; Fierens, Frans; Van Roozendael, Michel

    2017-05-01

    We present retrieval results of tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs), mapped at high spatial resolution over three Belgian cities, based on the DOAS analysis of Airborne Prism EXperiment (APEX) observations. APEX, developed by a Swiss-Belgian consortium on behalf of ESA (European Space Agency), is a pushbroom hyperspectral imager characterised by a high spatial resolution and high spectral performance. APEX data have been acquired under clear-sky conditions over the two largest and most heavily polluted Belgian cities, i.e. Antwerp and Brussels on 15 April and 30 June 2015. Additionally, a number of background sites have been covered for the reference spectra. The APEX instrument was mounted in a Dornier DO-228 aeroplane, operated by Deutsches Zentrum für Luft- und Raumfahrt (DLR). NO2 VCDs were retrieved from spatially aggregated radiance spectra allowing urban plumes to be resolved at the resolution of 60 × 80 m2. The main sources in the Antwerp area appear to be related to the (petro)chemical industry while traffic-related emissions dominate in Brussels. The NO2 levels observed in Antwerp range between 3 and 35 × 1015 molec cm-2, with a mean VCD of 17.4 ± 3.7 × 1015 molec cm-2. In the Brussels area, smaller levels are found, ranging between 1 and 20 × 1015 molec cm-2 and a mean VCD of 7.7 ± 2.1 × 1015 molec cm-2. The overall errors on the retrieved NO2 VCDs are on average 21 and 28 % for the Antwerp and Brussels data sets. Low VCD retrievals are mainly limited by noise (1σ slant error), while high retrievals are mainly limited by systematic errors. Compared to coincident car mobile-DOAS measurements taken in Antwerp and Brussels, both data sets are in good agreement with correlation coefficients around 0.85 and slopes close to unity. APEX retrievals tend to be, on average, 12 and 6 % higher for Antwerp and Brussels, respectively. Results demonstrate that the NO2 distribution in an urban environment, and its fine

  13. Validation of GOME (ERS-2) NO2 vertical column data with ground-based measurements at Issyk-Kul (Kyrgyzstan)

    Science.gov (United States)

    Ionov, D.; Sinyakov, V.; Semenov, V.

    Starting from 1995 the global monitoring of atmospheric nitrogen dioxide is carried out by the measurements of nadir-viewing GOME spectrometer aboard ERS-2 satellite. Continuous validation of that data by means of comparisons with well-controlled ground-based measurements is important to ensure the quality of GOME data products and improve related retrieval algorithms. At the station of Issyk-Kul (Kyrgyzstan) the ground-based spectroscopic observations of NO2 vertical column have been started since 1983. The station is located on the northern shore of Issyk-Kul lake, 1650 meters above the sea level (42.6 N, 77.0 E). The site is equipped with grating spectrometer for the twilight measurements of zenith-scattered solar radiation in the visible range, and applies the DOAS technique to retrieve NO2 vertical column. It is included in the list of NDSC stations as a complementary one. The present study is focused on validation of GOME NO2 vertical column data, based on 8-year comparison with correlative ground-based measurements at Issyk-Kul station in 1996-2003. Within the investigation, an agreement of both individual and monthly averaged GOME measurements with corresponding twilight ground-based observations is examined. Such agreement is analyzed with respect to different conditions (season, sun elevation), temporal/spatial criteria choice (actual overpass location, correction for diurnal variation) and data processing (GDP version 2.7, 3.0). In addition, NO2 vertical columns were integrated from simultaneous stratospheric profile measurements by NASA HALOE and SAGE-II/III satellite instruments and introduced to explain the differences with ground-based observations. In particular cases, NO2 vertical profiles retrieved from the twilight ground-based measurements at Issuk-Kul were also included into comparison. Overall, summertime GOME NO2 vertical columns were found to be systematicaly lower than ground-based data. This work was supported by International Association

  14. Two Catacombs of Late Sarmatian Time From Pashkovsky Burial Mound no. 2

    OpenAIRE

    Limberis Natalya Yuryevna; Marchenko Ivan Ivanovich

    2015-01-01

    The article deals with two burials from the Kuban basin region excavated in Pashkovsky burial mound no. 2 belonging to Maeotian Pashkovskoe ancient settlement. The burials were made in catacombs of similar construction and orientation. The narrow grave entrances and grave chambers are situated in-line. The grave chambers of the catacombs adjoin one other that probably was the reason for plunder of a little earlier burial no. 2. There were the complete horse skeleton, the cow skull and the she...

  15. In optics humidity compensation in NDIR exhaust gas measurements of NO2

    DEFF Research Database (Denmark)

    Stolberg-Rohr, Thomine Kirstine; Buchner, Rainer; Clausen, Sønnik

    2015-01-01

    NDIR is proposed for monitoring of air pollutants emitted by ship engines. Careful optical filtering overcomes the challenge of optical detection of NO2 in humid exhaust gas, despite spectroscopic overlap with the water vapour band. © 2014 OSA.......NDIR is proposed for monitoring of air pollutants emitted by ship engines. Careful optical filtering overcomes the challenge of optical detection of NO2 in humid exhaust gas, despite spectroscopic overlap with the water vapour band. © 2014 OSA....

  16. Validation of NO2 and NO from the Atmospheric Chemistry Experiment (ACE

    Directory of Open Access Journals (Sweden)

    M. Schneider

    2008-10-01

    Full Text Available Vertical profiles of NO2 and NO have been obtained from solar occultation measurements by the Atmospheric Chemistry Experiment (ACE, using an infrared Fourier Transform Spectrometer (ACE-FTS and (for NO2 an ultraviolet-visible-near-infrared spectrometer, MAESTRO (Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation. In this paper, the quality of the ACE-FTS version 2.2 NO2 and NO and the MAESTRO version 1.2 NO2 data are assessed using other solar occultation measurements (HALOE, SAGE II, SAGE III, POAM III, SCIAMACHY, stellar occultation measurements (GOMOS, limb measurements (MIPAS, OSIRIS, nadir measurements (SCIAMACHY, balloon-borne measurements (SPIRALE, SAOZ and ground-based measurements (UV-VIS, FTIR. Time differences between the comparison measurements were reduced using either a tight coincidence criterion, or where possible, chemical box models. ACE-FTS NO2 and NO and the MAESTRO NO2 are generally consistent with the correlative data. The ACE-FTS and MAESTRO NO2 volume mixing ratio (VMR profiles agree with the profiles from other satellite data sets to within about 20% between 25 and 40 km, with the exception of MIPAS ESA (for ACE-FTS and SAGE II (for ACE-FTS (sunrise and MAESTRO and suggest a negative bias between 23 and 40 km of about 10%. MAESTRO reports larger VMR values than the ACE-FTS. In comparisons with HALOE, ACE-FTS NO VMRs typically (on average agree to ±8% from 22 to 64 km and to +10% from 93 to 105 km, with maxima of 21% and 36%, respectively. Partial column comparisons for NO2 show that there is quite good agreement between the ACE instruments and the FTIRs, with a mean difference of +7.3% for ACE-FTS and +12.8% for MAESTRO.

  17. HCHO and NO2 MAXDOAS retrieval strategies harmonization: Recent results from the EU FP7 project QA4ECV

    Science.gov (United States)

    Pinardi, Gaia; Peters, Enno; Hendrick, François; Gielen, Clio; Van Roozendael, Michel; Richter, Andreas; Piters, Ankie; Wagner, Thomas; Wang, Yang; Drosoglou, Theano; Bais, Alkis; Wang, Shanshan; Saiz-Lopez, Alfonso

    2016-04-01

    During the last decade, it has been extensively demonstrated that MAXDOAS is a useful and reliable technique to retrieve integrated column amounts of tropospheric trace gases and aerosols, as well as information on their vertical distributions. Since it is based on optical remote-sensing in the UV-visible region like nadir backscatter space-borne sensors, MAXDOAS is also increasingly recognized as a reference technique for validating satellite nadir observations of air quality species like NO2 and HCHO. However, building up an harmonized network of MAXDOAS spectrometers requires significant efforts in terms of common retrieval strategies and best-practices definitions. Within the EU FP7 project QA4ECV (Quality Assurance for Essential Climate Variables; see http://www.qa4ecv.eu/), harmonization activities have been initiated focusing on the two main steps of the MAXDOAS retrieval, i.e. the DOAS spectral fit providing the so-called differential slant column densities (DSCDs) and the conversion of the retrieved DSCDs to vertical profiles and/or vertical column densities (VCDs). Regarding the first step, the DOAS settings for HCHO and NO2 are optimized through an intercomparison exercise of slant column retrievals involving 15 groups of the MAXDOAS community including the QA4ECV partners, and based on the radiance spectra acquired during the MAD-CAT campaign held in Mainz (Germany) in June-July 2013 (see http://joseba.mpch-mainz.mpg.de/mad_cat.htm). The harmonization of the second step is done through the application of an AMF (aim mass factor) look-up table (LUT) approach on the optimized NO2 and HCHO DSCDs. The AMF LUTs depend on entry parameters like SZA, elevation and relative azimuth angles, wavelength, boundary layer height, AOD, and surface albedo. The advantages and drawbacks of the LUT approach are illustrated at several stations through comparison of the derived VCDs with those retrieved using the more sophisticated Optimal-Estimation-based profiling method

  18. Intercomparison of OMI NO2 and HCHO air mass factor calculations: recommendations and best practices for retrievals

    Science.gov (United States)

    Lorente Delgado, Alba; Klaas Boersma, Folkert; Hilboll, Andreas; Richter, Andreas; Yu, Huan; van Roozendael, Michel; Dörner, Steffen; Wagner, Thomas; Barkley, Michael; Lamsal, Lok; Lin, Jintai; Liu, Mengyao

    2016-04-01

    We present a detailed comparison of the air mass factor (AMF) calculation process used by various research groups for OMI satellite retrievals of NO2 and HCHO. Although satellite retrievals have strongly improved over the last decades, there is still a need to better understand and reduce the uncertainties associated with every retrieval step of satellite data products, such as the AMF calculation. Here we compare and evaluate the different approaches used to calculate AMFs by several scientific groups (KNMI (WUR), IASB-BIRA, IUP-UNI. BREMEN, MPI-C, NASA GSFC, LEICESTER UNI. and PEKING UNI.). Each group calculated altitude dependent (box-) AMFs and clear sky and total tropospheric AMFs for several OMI orbits. First, European groups computed AMFs for one OMI orbit using common settings for the choice of surface albedo data, terrain height, cloud treatment and a priori vertical profile. Second, every group computed AMFs for two complete days in different seasons using preferred settings for the ancillary data and cloud treatment as a part of a Round Robin exercise. Box-AMFs comparison showed good consistency and underlined the importance of a correct treatment of the physical processes affecting the effective light path and the vertical discretization of the atmosphere. Using common settings, tropospheric NO2 AMFs in polluted pixels on average agreed within 4.7% whereas in remote pixels agreed within 3.5%. Using preferred settings relative differences between AMFs increase up to 15-30%. This increase is traced back to the different choices and assumptions made throughout the AMF calculation, which affect the final AMF values and thus the uncertainty in the AMF calculation. Differences between state of the art cloud treatment approaches highlight the importance of an accurate cloud correction: total and clear sky AMFs in polluted conditions differ by up to 40% depending on the retrieval scenario. Based on the comparison results, specific recommendations on best

  19. Trace conditioning in insects—keep the trace!

    Science.gov (United States)

    Dylla, Kristina V.; Galili, Dana S.; Szyszka, Paul; Lüdke, Alja

    2013-01-01

    Trace conditioning is a form of associative learning that can be induced by presenting a conditioned stimulus (CS) and an unconditioned stimulus (US) following each other, but separated by a temporal gap. This gap distinguishes trace conditioning from classical delay conditioning, where the CS and US overlap. To bridge the temporal gap between both stimuli and to form an association between CS and US in trace conditioning, the brain must keep a neural representation of the CS after its termination—a stimulus trace. Behavioral and physiological studies on trace and delay conditioning revealed similarities between the two forms of learning, like similar memory decay and similar odor identity perception in invertebrates. On the other hand differences were reported also, like the requirement of distinct brain structures in vertebrates or disparities in molecular mechanisms in both vertebrates and invertebrates. For example, in commonly used vertebrate conditioning paradigms the hippocampus is necessary for trace but not for delay conditioning, and Drosophila delay conditioning requires the Rutabaga adenylyl cyclase (Rut-AC), which is dispensable in trace conditioning. It is still unknown how the brain encodes CS traces and how they are associated with a US in trace conditioning. Insects serve as powerful models to address the mechanisms underlying trace conditioning, due to their simple brain anatomy, behavioral accessibility and established methods of genetic interference. In this review we summarize the recent progress in insect trace conditioning on the behavioral and physiological level and emphasize similarities and differences compared to delay conditioning. Moreover, we examine proposed molecular and computational models and reassess different experimental approaches used for trace conditioning. PMID:23986710

  20. Trace conditioning in insects-keep the trace!

    Science.gov (United States)

    Dylla, Kristina V; Galili, Dana S; Szyszka, Paul; Lüdke, Alja

    2013-01-01

    Trace conditioning is a form of associative learning that can be induced by presenting a conditioned stimulus (CS) and an unconditioned stimulus (US) following each other, but separated by a temporal gap. This gap distinguishes trace conditioning from classical delay conditioning, where the CS and US overlap. To bridge the temporal gap between both stimuli and to form an association between CS and US in trace conditioning, the brain must keep a neural representation of the CS after its termination-a stimulus trace. Behavioral and physiological studies on trace and delay conditioning revealed similarities between the two forms of learning, like similar memory decay and similar odor identity perception in invertebrates. On the other hand differences were reported also, like the requirement of distinct brain structures in vertebrates or disparities in molecular mechanisms in both vertebrates and invertebrates. For example, in commonly used vertebrate conditioning paradigms the hippocampus is necessary for trace but not for delay conditioning, and Drosophila delay conditioning requires the Rutabaga adenylyl cyclase (Rut-AC), which is dispensable in trace conditioning. It is still unknown how the brain encodes CS traces and how they are associated with a US in trace conditioning. Insects serve as powerful models to address the mechanisms underlying trace conditioning, due to their simple brain anatomy, behavioral accessibility and established methods of genetic interference. In this review we summarize the recent progress in insect trace conditioning on the behavioral and physiological level and emphasize similarities and differences compared to delay conditioning. Moreover, we examine proposed molecular and computational models and reassess different experimental approaches used for trace conditioning.

  1. Trace conditioning in insects – Keep the trace!

    Directory of Open Access Journals (Sweden)

    Kristina V Dylla

    2013-08-01

    Full Text Available Trace conditioning is a form of associative learning that can be induced by presenting a conditioned stimulus (CS and an unconditioned stimulus (US following each other, but separated by a temporal gap. This gap distinguishes trace conditioning from classical delay conditioning, where the CS and US overlap. To bridge the temporal gap between both stimuli and to form an association between CS and US in trace conditioning, the brain must keep a neural representation of the CS after its termination – a stimulus trace. Behavioral and physiological studies on trace and delay conditioning revealed similarities between the two forms of learning, like similar memory decay and similar odor identity perception in invertebrates. On the other hand differences were reported also, like the requirement of distinct brain structures in vertebrates or disparities in molecular mechanisms in both vertebrates and invertebrates. For example, in commonly used vertebrate conditioning paradigms the hippocampus is necessary for trace but not for delay conditioning, and Drosophila delay conditioning requires the Rutabaga adenylyl cyclase, which is dispensable in trace conditioning. It is still unknown how the brain encodes CS traces and how they are associated with a US in trace conditioning. Insects serve as powerful models to address the mechanisms underlying trace conditioning, due to their simple brain anatomy, behavioral accessibility and established methods of genetic interference. In this review we summarize the recent progress in insect trace conditioning on the behavioral and physiological level and emphasize similarities and differences compared to delay conditioning. Moreover, we examine proposed molecular and computational models and reassess different experimental approaches used for trace conditioning.

  2. Mesoporous WN/WO3-Composite Nanosheets for the Chemiresistive Detection of NO2 at Room Temperature

    Directory of Open Access Journals (Sweden)

    Fengdong Qu

    2016-07-01

    Full Text Available Composite materials, which can optimally use the advantages of different materials, have been studied extensively. Herein, hybrid tungsten nitride and oxide (WN/WO3 composites were prepared through a simple aqueous solution route followed by nitriding in NH3, for application as novel sensing materials. We found that the introduction of WN can improve the electrical properties of the composites, thus improving the gas sensing properties of the composites when compared with bare WO3. The highest sensing response was up to 21.3 for 100 ppb NO2 with a fast response time of ~50 s at room temperature, and the low detection limit was 1.28 ppb, which is far below the level that is immediately dangerous to life or health (IDLH values (NO2: 20 ppm defined by the U.S. National Institute for Occupational Safety and Health (NIOSH. In addition, the composites successfully lower the optimum temperature of WO3 from 300 °C to room temperature, and the composites-based sensor presents good long-term stability for NO2 of 100 ppb. Furthermore, a possible sensing mechanism is proposed.

  3. The effect of dietary vitamin A on NO2 exposure on the hamster lung

    International Nuclear Information System (INIS)

    Kim, J.C.

    1978-01-01

    The effect of dietary vitamin A and NO2 exposure on the hamster lung was evaluated by histopathology, electron microscopy, and thymidine uptake studies. Hamsters were maintained on deficient (0 micrograms), adequate (100 micrograms), and high (200 micrograms) dose levels of vitamin A while being exposed repeatedly to 10 ppm of NO2 for 5 hours once a week over an 8-week period. Hamsters of the deficient group exhibited clinical and morphologic changes characteristic of vitamin A deficiency. Animals maintained on adequate and high dose levels of vitamin A were not affected by vitamin A deficiency. Hypertrophy and hyperplasia of the epithelial cells of the terminal bronchiolar alveolar region of lungs of adequately and highly dosed animals were greater than those observed in the deficient animals, when NO2 exposure was given. However, the extent of the lesions observed in all three groups was less than that seen in normal hamsters given a single, 5-hour NO2 exposure. Ultrastructural changes observed in vitamin A-deficient hamsters exposed to NO2 were hypertrophy and hyperplasia of bronchiolar epithelial cells, diffuse loss of cilia, membrane damage, and mitochondrial damage manifested by calcium deposition. Tritiated thymidine uptake studies of lungs of animals exposed repeatedly revealed a rather erratic cell renewal pattern following NO2 exposure in comparison to the group of animals exposed singly

  4. Modification of a commercial cavity ring-down spectroscopy NO2 detector for enhanced sensitivity

    International Nuclear Information System (INIS)

    Castellanos, Patricia; Ehrman, Sheryl H.; Luke, Winston T.; Kelley, Paul; Stehr, Jeffrey W.; Dickerson, Russell R.

    2009-01-01

    Nitrogen dioxide (NO 2 ) plays a central role in atmospheric chemistry, air pollution, and biogeochemical cycles. Many analytical techniques have been developed to detect NO 2 , but only chemiluminescence-based instruments are commonly, commercially available. There remains a need for a fast, light, and simple method to directly measure NO 2 . In this work we describe the modification and characterization of a small, commercially available cavity ring-down spectroscopy (CRDS) NO 2 detector suitable for surface and aircraft monitoring. A metal oxide scrubber was added to remove NO 2 , and provide a chemical zero, improving the detection limit (3σ of the background noise) from several parts per billion by volume (ppbv) to 0.06 ppbv, integrated over 60 s. Known interferences by water and particles were removed using Nafion tubing and a 1 μm Teflon filter, respectively. A 95% response time of 18±1 s was observed for a step change in concentration. The CRDS detector was run in parallel to an ozone chemiluminescence device with photolytic conversion of NO 2 to NO. The two instruments measured ambient air in suburban Maryland. A least-squares fit to the comparison data resulted a slope of 0.960±0.002 and R of 0.995, showing agreement within experimental uncertainty.

  5. National patterns in environmental injustice and inequality: outdoor NO2 air pollution in the United States.

    Directory of Open Access Journals (Sweden)

    Lara P Clark

    Full Text Available We describe spatial patterns in environmental injustice and inequality for residential outdoor nitrogen dioxide (NO2 concentrations in the contiguous United States. Our approach employs Census demographic data and a recently published high-resolution dataset of outdoor NO2 concentrations. Nationally, population-weighted mean NO2 concentrations are 4.6 ppb (38%, p2.5 hours/week of physical activity. Inequality for NO2 concentration is greater than inequality for income (Atkinson Index: 0.11 versus 0.08. Low-income nonwhite young children and elderly people are disproportionately exposed to residential outdoor NO2. Our findings establish a national context for previous work that has documented air pollution environmental injustice and inequality within individual US metropolitan areas and regions. Results given here can aid policy-makers in identifying locations with high environmental injustice and inequality. For example, states with both high injustice and high inequality (top quintile for outdoor residential NO2 include New York, Michigan, and Wisconsin.

  6. Absorption of NO and NO2in Caprolactam Tetrabutyl Ammonium Halide Ionic Liquids.

    Science.gov (United States)

    Duan, Erhong; Guo, Bin; Zhang, Dandan; Shi, Long; Sun, Hua; Wang, Yanan

    2011-12-01

    To explore environmentally benign solvents for the absorption of NO and NO 2 , a series of caprolactam tetrabutyl ammonium halide ionic liquids were synthesized. The solubility of NO and NO 2 was measured at temperatures ranging from 298.2 to 363.2 K and atmospheric pressure, and the following trend in the solubility of NO and NO 2 in ionic liquids with various halide anions was observed, respectively: F > Br > Cl and Br > Cl > F. Moreover, as the temperature increased from 308.15 to 363.15 K and the mole ratio of caprolactam increased from 2:1 to 6:1, the solubility of NO increased. Alternatively, the solubility of NO 2 decreased as the temperature increased from 298.15 to 363.15 K, and the mole ratio of caprolactam increased from 2:1 to 6:1. The absorption and desorption of NO and NO 2 was practically reversible in the ionic liquids, which was characterized by nuclear magnetic resonance. The method, which is at least partially reversible, offers interesting possibilities for the removal of NO and NO 2 . [Box: see text].

  7. Study of quartz crystal microbalance NO2 sensor coated with sputtered indium tin oxide film

    International Nuclear Information System (INIS)

    Georgieva, V; Gadjanova, V; Angelov, Ts; Aleksandrova, M; Acad. Georgi Bonchev str.bl. 11, 1113, Sofia (Bulgaria))" data-affiliation=" (Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. Georgi Bonchev str.bl. 11, 1113, Sofia (Bulgaria))" >Stefanov, P; Acad. Georgi Bonchev str.bl. 11, 1113, Sofia (Bulgaria))" data-affiliation=" (Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. Georgi Bonchev str.bl. 11, 1113, Sofia (Bulgaria))" >Dilova, T; Grechnikov, A

    2014-01-01

    A study of NO 2 gas sorption ability of thin indium tin oxide (ITO) deposited on 16 MHz quartz crystal microbalance (QCM) is presented. ITO films are grown by RF sputtering of indium/tin target with weight proportion 95:5 in oxygen environment. The ITO films have been characterized by X-ray photoelectron spectroscopy measurements. The ITO surface composition in atomic % is defined to be: In-40.6%, Sn-4.3% and O-55%. The thickness and refractive index of the films are determined by ellipsometric method. The frequency shift of QCM-ITO is measured at different NO 2 concentrations. The QCM-ITO system becomes sensitive at NO 2 concentration ≥ 500 ppm. The sorbed mass for each concentration is calculated according the Sauerbrey equation. The results indicated that the 1.09 ng of the gas is sorbed into 150 nm thick ITO film at 500 ppm NO 2 concentration. When the NO 2 concentration increases 10 times the calculated loaded mass is 5.46 ng. The sorption process of the gas molecules is defined as reversible. The velocity of sorbtion /desorption processes are studied, too. The QCM coated with thin ITO films can be successfully used as gas sensors for detecting NO 2 in the air at room temperature

  8. Tracing Planets in Circumstellar Discs

    Directory of Open Access Journals (Sweden)

    Uribe Ana L.

    2013-04-01

    Full Text Available Planets are assumed to form in circumstellar discs around young stellar objects. The additional gravitational potential of a planet perturbs the disc and leads to characteristic structures, i.e. spiral waves and gaps, in the disc density profile. We perform a large-scale parameter study on the observability of these planet-induced structures in circumstellar discs in the (submm wavelength range for the Atacama Large (SubMillimeter Array (ALMA. On the basis of hydrodynamical and magneto-hydrodynamical simulations of star-disc-planet models we calculate the disc temperature structure and (submm images of these systems. These are used to derive simulated ALMA maps. Because appropriate objects are frequent in the Taurus-Auriga region, we focus on a distance of 140 pc and a declination of ≈ 20°. The explored range of star-disc-planet configurations consists of six hydrodynamical simulations (including magnetic fields and different planet masses, nine disc sizes with outer radii ranging from 9 AU to 225 AU, 15 total disc masses in the range between 2.67·10-7 M⊙ and 4.10·10-2 M⊙, six different central stars and two different grain size distributions, resulting in 10 000 disc models. At almost all scales and in particular down to a scale of a few AU, ALMA is able to trace disc structures induced by planet-disc interaction or the influence of magnetic fields in the wavelength range between 0.4...2.0 mm. In most cases, the optimum angular resolution is limited by the sensitivity of ALMA. However, within the range of typical masses of protoplane tary discs (0.1 M⊙...0.001 M⊙ the disc mass has a minor impact on the observability. At the distance of 140 pc it is possible to resolve discs down to 2.67·10-6 M⊙ and trace gaps in discs with 2.67·10-4 M⊙ with a signal-to-noise ratio greater than three. In general, it is more likely to trace planet-induced gaps in magneto-hydrodynamical disc models, because gaps are wider in the presence of

  9. Characteristics of Beach Seine Fishery of East Java: Facing Ministerial Decree of Marine Affairs and Fisheries No. 2/2015

    Directory of Open Access Journals (Sweden)

    Dewa Gede Raka Wiadnya

    2017-07-01

    Full Text Available Catch biomass and time-trend perception of Beach seine fishery were studied during 2015, from four different sites in East Java: Padikde Madura, Santan Island Banyuwangi, Prigi Beach Trenggalek, and Dangkal Beach Pacitan. The study aimed to assess the impact of recently Ministerial Decree (No. 2/2015 on this particular fishery. Catch biomass was analyzed based on swept area method. Time trend perception was traced back from fishermen in relation to reduced catch biomass, catch size, habitat degradation, and income contribution from the fishery. The results showed that Beach Seines in East Java are considerably subsistence. It swept fixed-bottom habitats of 1–9 ha. Average catch biomass for all sites was 15±19.4 kg trip-1. With low price of fish catch, fishermen cannot place down their family income solely from this livelihood. Beach seine is more as to maintain tradition of subsistence. Fishermen clearly observed the reduced in catch biomass and catch size compared to what it used to be (±30 years ago. With very low contribution to total catch in the region, negligible impact to habitat degradation, and consumed no fuel subsidy, it is no real reason to include this gear in general ban through Ministerial Decree of Marine Affairs and Fisheries.

  10. General Labour Code (Act No. 2 of 1986), 5 April 1986. [Selected provisions].

    Science.gov (United States)

    1989-01-01

    Guinea-Bissau's General Labor Code, Act No. 2 of 1986, requires that employers adopt non-discriminatory procedures in dealing with their employees, disallowing discrimination based on gender, race, national origin, religion, political ideology or inclination, or on whether or not an employee is affiliated to a worker's union. Women are guaranteed equality with men in work opportunity and employment treatment; they are assured access to any type of job, profession, or position which does not pose any potential or actual threat to their genetic functioning. Additional legislation shall establish the conditions and prohibitions for contracting woman for heavy labor, for jobs performed under insalubrious conditions, for underground work, and for other types of jobs which might endanger a woman's genetic functioning. Job offers must not discriminate, unless the restrictions or specifications are essential to the nature of the job, rendering the job qualitatively differentiable when performed by a man or a woman. The employer must ensure that female workers have the same job opportunity and treatment for professional training and career development. Different specific job categories may not be created for men and women if a woman's salary is inferior to that of a man performing equivalent work in a corresponding professional category. Protection during pregnancy and delivery guarantees a woman the right to decline medically inadvisable tasks without loss of wages; to decline overtime work; to be absent from work when necessary for maternal medical care without loss of wages; to interrupt daily work to nurse her children for 1 hour or 2 for half-hour periods for up to 1 year without the loss of wages. Every female employee has the right to 60 days pregnancy and maternity leave, without loss of wages, for whatever clinical type of delivery, including for still births and for births where the infant died shortly thereafter.

  11. Use of passive diffusion sampling method for defining NO2 concentrations gradient in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Meliefste Kees

    2006-06-01

    Full Text Available Abstract Background Air pollution in São Paulo is constantly being measured by the State of Sao Paulo Environmental Agency, however there is no information on the variation between places with different traffic densities. This study was intended to identify a gradient of exposure to traffic-related air pollution within different areas in São Paulo to provide information for future epidemiological studies. Methods We measured NO2 using Palmes' diffusion tubes in 36 sites on streets chosen to be representative of different road types and traffic densities in São Paulo in two one-week periods (July and August 2000. In each study period, two tubes were installed in each site, and two additional tubes were installed in 10 control sites. Results Average NO2 concentrations were related to traffic density, observed on the spot, to number of vehicles counted, and to traffic density strata defined by the city Traffic Engineering Company (CET. Average NO2concentrations were 63μg/m3 and 49μg/m3 in the first and second periods, respectively. Dividing the sites by the observed traffic density, we found: heavy traffic (n = 17: 64μg/m3 (95% CI: 59μg/m3 – 68μg/m3; local traffic (n = 16: 48μg/m3 (95% CI: 44μg/m3 – 52μg/m3 (p Conclusion The differences in NO2 levels between heavy and local traffic sites are large enough to suggest the use of a more refined classification of exposure in epidemiological studies in the city. Number of vehicles counted, traffic density observed on the spot and traffic density strata defined by the CET might be used as a proxy for traffic exposure in São Paulo when more accurate measurements are not available.

  12. Operational total and tropospheric NO2 column retrieval for GOME-2

    Directory of Open Access Journals (Sweden)

    M. Van Roozendael

    2011-07-01

    Full Text Available This paper presents the algorithm for the operational near real time retrieval of total and tropospheric NO2 columns from the Global Ozone Monitoring Experiment (GOME-2. The retrieval is performed with the GOME Data Processor (GDP version 4.4 as used by the EUMETSAT Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF. The differential optical absorption spectroscopy (DOAS method is used to determine NO2 slant columns from GOME-2 (irradiance data in the 425–450 nm range. Initial total NO2 columns are computed using stratospheric air mass factors, and GOME-2 derived cloud properties are used to calculate the air mass factors for scenarios in the presence of clouds. To obtain the stratospheric NO2 component, a spatial filtering approach is used, which is shown to be an improvement on the Pacific reference sector method. Tropospheric air mass factors are computed using monthly averaged NO2 profiles from the MOZART-2 chemistry transport model. An error analysis shows that the random error in the GOME-2 NO2 slant columns is approximately 0.45 × 1015 molec cm−2. As a result of the improved quartz diffuser plate used in the GOME-2 instrument, the systematic error in the slant columns is strongly reduced compared to GOME/ERS-2. The estimated uncertainty in the GOME-2 tropospheric NO2 column for polluted conditions ranges from 40 to 80 %. An end-to-end ground-based validation approach for the GOME-2 NO2 columns is illustrated based on multi-axis MAXDOAS measurements at the Observatoire de Haute Provence (OHP. The GOME-2 stratospheric NO2 columns are found to be in good overall agreement with coincident ground-based measurements at OHP. A time series of the MAXDOAS and the GOME-2 tropospheric NO2 columns shows that pollution episodes at OHP are well captured by GOME-2. Monthly mean tropospheric columns are in very good agreement, with differences generally within 0.5 × 1015 molec cm−2.

  13. Traces generating what was there

    CERN Document Server

    2017-01-01

    Traces keep time contained and make visible what was there. Going back to the art of trace-reading, they continue to be a fundamental resource for scientific knowledge production. The contributions study, from the biology laboratory to the large colliders of particle physics, techniques involved in the production of material traces. Following their changes over two centuries, this collection shows the continuities they have in the digital age.

  14. Lidar Detection of Explosives Traces

    Directory of Open Access Journals (Sweden)

    Bobrovnikov Sergei M.

    2016-01-01

    Full Text Available The possibility of remote detection of traces of explosives using laser fragmentation/laser-induced fluorescence (LF/LIF is studied. Experimental data on the remote visualization of traces of trinitrotoluene (TNT, hexogen (RDX, trotyl-hexogen (Comp B, octogen (HMX, and tetryl with a scanning lidar detector of traces of nitrogen-containing explosives at a distance of 5 m are presented.

  15. Estimating Western U.S. Oil & Gas Emissions with OMI NO2 Data

    Science.gov (United States)

    Clifton, O. E.; Holloway, T.; Oberman, J.

    2012-12-01

    In the last ten years, there has been a steep increase in the number natural gas and oil extraction facilities in the United States due to hydraulic fracturing ("fracking"). Each facility requires a large range of equipment, such as drilling rigs, compressor engines, heaters, and pneumatic devices. These activities can lead to elevated nitrogen dioxide (NO2) emissions in rural areas, often in regions without routine NO2 surface monitoring. Furthermore, permitting rules vary from state to state, and many new extraction facilities are unpermitted and exact emissions unknown. On April 18, 2012, the EPA announced air pollution standards for volatile organic compounds (VOCs) emissions from the oil and gas industry. Until 2015, when these standards must be in effect, NOx (NO2 + NO) will continue to react with VOCs to form unhealthy levels of tropospheric ozone in regions with heavy use of hydraulic fracturing. In order to identify areas of elevated NO2 emissions and constrain associated on-road and off-road sources in areas with prominent shale basins and known drilling, we employ remote sensing estimates of column NO2 from the Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite. OMI NO2 is sensitive to the planetary boundary layer and to surface air pollution and thus has high temporal and spatial variation. These Level-2 satellite data are processed with the Wisconsin Horizontal Interpolation Program for Satellites (WHIPS), developed at the University of Wisconsin-Madison. We interpolate the data to allow further ease in mapping change in NO2 associated with drilling, and the quantification of pollution trends attributable to hydraulic-fracturing in the Western U.S. from 2004 to the present.

  16. High-resolution NO2 observations from the Airborne Compact Atmospheric Mapper: Retrieval and validation

    Science.gov (United States)

    Lamsal, L. N.; Janz, S. J.; Krotkov, N. A.; Pickering, K. E.; Spurr, R. J. D.; Kowalewski, M. G.; Loughner, C. P.; Crawford, J. H.; Swartz, W. H.; Herman, J. R.

    2017-02-01

    Nitrogen dioxide (NO2) is a short-lived atmospheric pollutant that serves as an air quality indicator and is itself a health concern. The Airborne Compact Atmospheric Mapper (ACAM) was flown on board the NASA UC-12 aircraft during the Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality Maryland field campaign in July 2011. The instrument collected hyperspectral remote sensing measurements in the 304-910 nm range, allowing daytime observations of several tropospheric pollutants, including nitrogen dioxide (NO2), at an unprecedented spatial resolution of 1.5 × 1.1 km2. Retrievals of slant column abundance are based on the differential optical absorption spectroscopy method. For the air mass factor computations needed to convert these retrievals to vertical column abundance, we include high-resolution information for the surface reflectivity by using bidirectional reflectance distribution function data from the Moderate Resolution Imaging Spectroradiometer. We use high-resolution simulated vertical distributions of NO2 from the Community Multiscale Air Quality and Global Modeling Initiative models to account for the temporal variation in atmospheric NO2 to retrieve middle and lower tropospheric NO2 columns (NO2 below the aircraft). We compare NO2 derived from ACAM measurements with in situ observations from NASA's P-3B research aircraft, total column observations from the ground-based Pandora spectrometers, and tropospheric column observations from the space-based Ozone Monitoring Instrument. The high-resolution ACAM measurements not only give new insights into our understanding of atmospheric composition and chemistry through observation of subsampling variability in typical satellite and model resolutions, but they also provide opportunities for testing algorithm improvements for forthcoming geostationary air quality missions.

  17. Trace-element analysis in environmental sciences

    International Nuclear Information System (INIS)

    Valkovic, V.; Moschini, G.

    1988-01-01

    The use of charged-particle accelerators in trace-element analysis in the field of environmental sciences is described in this article. Nuclear reactions, charged-particle-induced X-ray emission as well as other nuclear and atomic processes can be used individually, or combined, in developing adequate analytical systems. In addition to concentration levels, concentration levels, concentration profiles can be measured, resulting in unique information. Some examples of experiments performed are described together with the suggestions for future measurements [pt

  18. Trace analysis of semiconductor materials

    CERN Document Server

    Cali, J Paul; Gordon, L

    1964-01-01

    Trace Analysis of Semiconductor Materials is a guidebook concerned with procedures of ultra-trace analysis. This book discusses six distinct techniques of trace analysis. These techniques are the most common and can be applied to various problems compared to other methods. Each of the four chapters basically includes an introduction to the principles and general statements. The theoretical basis for the technique involved is then briefly discussed. Practical applications of the techniques and the different instrumentations are explained. Then, the applications to trace analysis as pertaining

  19. Trace Mineral Losses in Sweat

    National Research Council Canada - National Science Library

    Chinevere, Troy D; McClung, James P; Cheuvront, Samuel N

    2007-01-01

    Copper, iron and zinc are nutritionally essential trace minerals that confer vital biological roles including the maintenance of cell structure and integrity, regulation of metabolism, immune function...

  20. Tracing Cultural Memory

    DEFF Research Database (Denmark)

    Wiegand, Frauke Katharina

    to Soweto’s Regina Mundi Church, this thesis analyses tourists’ snapshots at sites of memory and outlines their tracing activity in cultural memory. It draws on central concepts of actor - network theory and visual culture studies for a cross - disciplinary methodology to comprehend the collective...... of memory. They highlight the role of mundane uses of the past and indicate the need for cross - disciplinary research on the visual and on memory......We encounter, relate to and make use of our past and that of others in multifarious and increasingly mobile ways. Tourism is one of the main paths for encountering sites of memory. This thesis examines tourists’ creative appropriations of sites of memory – the objects and future memories inspired...

  1. Observations of ClNO2 and PANs in a mid-continental urban environment

    Science.gov (United States)

    Furgeson, A.; Mielke, L.; Osthoff, H. D.

    2010-12-01

    Nitrogen oxides play many important roles in regional air quality, for example, through the catalytic photochemical production of O3 involving NOx (=NO+NO2), which in urban environments is primarily of anthropogenic origin. NOx can be converted to reservoir species, such as peroxyacyl nitrates (PANs), or removed from the atmosphere, mainly by conversion to HNO3, which is removed predominantly through heterogeneous uptake and dry deposition. The main HNO3 production pathways are reaction of NO2 with OH during the day and heterogeneous reactions involving N2O5 at night. It has been known for some time that heterogeneous N2O5 hydrolysis (i.e., N2O5 + H2O → 2HNO3) competes with ClNO2 formation (i.e., N2O5 + Cl- → ClNO2 + NO3-) on chloride containing aerosol, but the latter reaction is believed to be only of significance in marine and coastal environments. Formation of ClNO2 is significant as it reduces the rate of nocturnal NOx removal and activates chlorine by releasing highly reactive Cl atoms following ClNO2 photolysis after sunrise. Recent field measurements by Thornton and coworkers have shown the efficient formation of ClNO2 in mid-continental air at a distance greater than 1,000 km from the nearest coastline. In this presentation, measurements of peroxyacyl nitrates and ClNO2 by chemical ionization mass spectrometry (CIMS) on the rooftop of a 6-story building in Calgary, Alberta, Canada, are described. The CIMS was operated in negative ion mode and equipped with a heated inlet to dissociate PANs to NO2 and the corresponding PA radicals, which are converted to the respective carboxylate anions using iodide reagent ion. ClNO2 was monitored as the cluster ion (ClNO2)I- at m/z 208 and 210. The CIMS was calibrated for peroxyacyl nitrates using a newly developed photolysis source, which was also used to deliver an internal standard during the measurement intensive. Measurements took place during spring and fall of 2010. During spring, we observed in excess of 200

  2. OMI NO2 column densities over North American urban cities: the effect of satellite footprint resolution

    Science.gov (United States)

    Kim, Hyun Cheol; Lee, Pius; Judd, Laura; Pan, Li; Lefer, Barry

    2016-03-01

    Nitrogen dioxide vertical column density (NO2 VCD) measurements via satellite are compared with a fine-scale regional chemistry transport model, using a new approach that considers varying satellite footprint sizes. Space-borne NO2 VCD measurement has been used as a proxy for surface nitrogen oxide (NOx) emission, especially for anthropogenic urban emission, so accurate comparison of satellite and modeled NO2 VCD is important in determining the future direction of NOx emission policy. The NASA Ozone Monitoring Instrument (OMI) NO2 VCD measurements, retrieved by the Royal Netherlands Meteorological Institute (KNMI), are compared with a 12 km Community Multi-scale Air Quality (CMAQ) simulation from the National Oceanic and Atmospheric Administration. We found that the OMI footprint-pixel sizes are too coarse to resolve urban NO2 plumes, resulting in a possible underestimation in the urban core and overestimation outside. In order to quantify this effect of resolution geometry, we have made two estimates. First, we constructed pseudo-OMI data using fine-scale outputs of the model simulation. Assuming the fine-scale model output is a true measurement, we then collected real OMI footprint coverages and performed conservative spatial regridding to generate a set of fake OMI pixels out of fine-scale model outputs. When compared to the original data, the pseudo-OMI data clearly showed smoothed signals over urban locations, resulting in roughly 20-30 % underestimation over major cities. Second, we further conducted conservative downscaling of OMI NO2 VCDs using spatial information from the fine-scale model to adjust the spatial distribution, and also applied averaging kernel (AK) information to adjust the vertical structure. Four-way comparisons were conducted between OMI with and without downscaling and CMAQ with and without AK information. Results show that OMI and CMAQ NO2 VCDs show the best agreement when both downscaling and AK methods are applied, with the correlation

  3. Untangling the Causes of Variation in ClNO2 Yield from the WINTER Campaign

    Science.gov (United States)

    Fibiger, D. L.; Lopez-Hilfiker, F.; McDuffie, E. E.; Dubé, W.; Lee, B. H.; Ebben, C. J.; Sparks, T.; Wooldridge, P. J.; Weinheimer, A. J.; Montzka, D.; Schroder, J. C.; Campuzano-Jost, P.; Guo, H.; Sullivan, A.; Dibb, J. E.; Weber, R. J.; Jimenez, J. L.; Cohen, R. C.; Thornton, J. A.; Brown, S. S.

    2016-12-01

    Nitrogen oxides play a key role in atmospheric chemistry. In the lower troposphere they catalyze ozone (O3) production during the day, while at night they react to form nitric acid and remove O3. While these processes are well studied in summertime, winter measurements are far more limited. While summer has more active photochemistry, in winter there is greater potential for longer-range transport of pollutants as they have longer lifetimes against photochemical or heterogeneous oxidation. As part of the Wintertime INvestigation of Transport, Emission and Reactivity (WINTER) campaign, aircraft-based measurements were made over the northeastern United States of oxidized nitrogen species, their precursors and products. At night, NOX (NO + NO2) reacts with O3 to form N2O5. The N2O5 can then be taken up onto aerosol particles where it forms either two HNO3 or HNO3 and ClNO2. The balance between these pathways is important for atmospheric chemistry the next day, as ClNO2 will photolyze to yield a NO2 molecule and a Cl radical. In contrast, HNO3 does not participate in further radical chemistry. Thus, formation of ClNO2 can lead to longer-range transport of NOX as well as radical production in less polluted areas. Laboratory studies suggest that the yield of ClNO2 is dependent on the relative concentrations of aerosol chloride and liquid water, but it is unknown whether these yields can be accurately predicted based on air mass history or measured ambient aerosol composition. The observed levels of ClNO2 varied significantly throughout the WINTER campaign from below detection limit to over 2 ppbv, while the yield of ClNO2 covered its entire possible range of 0 to 1. In this study we will use the wealth of data and wide range of observed values to constrain which factors are most important in determining ClNO2 yield and to compare these yields to recent parameterizations from laboratory studies.

  4. Effect of NO2 and water on the catalytic oxidation of soot

    DEFF Research Database (Denmark)

    Christensen, Jakob Munkholt; Grunwaldt, Jan-Dierk; Jensen, Anker Degn

    2017-01-01

    The influence of adding NO2 to 10 vol% O2/N2 on non-catalytic soot oxidation and soot oxidation in intimate or loose contact with a catalyst has been investigated. In non-catalytic soot oxidation the oxidation rate is increased significantly at lower temperatures by NO2. For soot oxidation in tig...... exhibited a volcano-curve dependence on the heat of oxygen chemisorption, and among the tested pure metals and oxides Cr2O3 was the most active catalyst. Further improvements were achieved with a FeaCrbOx binary oxide catalyst.......The influence of adding NO2 to 10 vol% O2/N2 on non-catalytic soot oxidation and soot oxidation in intimate or loose contact with a catalyst has been investigated. In non-catalytic soot oxidation the oxidation rate is increased significantly at lower temperatures by NO2. For soot oxidation in tight...... contact with a Co3O4 catalyst a more reactive NO2-containg atmosphere did not change the oxidation profile significantly during temperature programmed oxidation. This is consistent with the expected Mars van Krevelen mechanism, where the rate limiting step is reaction between carbon and lattice oxygen...

  5. In Situ Measurements of the NO2/NO Ratio for Testing Atmospheric Photochemical Models

    Science.gov (United States)

    Jaegle, L.; Webster, C. R.; May, R. D.; Fahey, D. W.; Woodbridge, E. L.; Keim, E. R.; Gao, R. S.; Proffitt, M. H.; Stimpfle, R. M.; Salawitch, R. J.

    1994-01-01

    Simultaneous in situ measurements of NO2, NO, O3, ClO, pressure and temperature have been made for the first time, presenting a unique opportunity to test our current understanding of the photochemistry of the lower stratosphere. Data were collected from several flights of the ER-2 aircraft at mid-latitudes in May 1993 during NASA's Stratospheric Photochemistry, Aerosols and Dynamics Expedition (SPADE). The daytime ratio of NO2/NO remains fairly constant at 19 km with a typical value of 0.68 and standard deviation of +/- 0.17. The ratio observations are compared with simple steady-state calculations based on laboratory-measured reaction rates and modeled NO2 photolysis rates. At each measurement point the daytime NO2/NO with its measurement uncertainty overlap the results of steady-state calculations and associated uncertainty. However, over all the ER-2 flights examined, the model systematically overestimates the ratio by 40% on average. Possible sources of error are examined in both model and measurements. It is shown that more accurate laboratory determinations of the NO + O3 reaction rate and of the NO2 cross-sections in the 200-220 K temperature range characteristic of the lower stratosphere would allow for a more robust test of our knowledge of NO(x) photochemistry by reducing significant sources of uncertainties in the interpretation of stratospheric measurements. The present measurements are compared with earlier observations of the ratio at higher altitudes.

  6. An MCM modeling study of nitryl chloride (ClNO2) impacts on oxidation, ozone production and nitrogen oxide partitioning in polluted continental outflow

    Science.gov (United States)

    Riedel, T. P.; Wolfe, G. M.; Danas, K. T.; Gilman, J. B.; Kuster, W. C.; Bon, D. M.; Vlasenko, A.; Li, S.-M.; Williams, E. J.; Lerner, B. M.; Veres, P. R.; Roberts, J. M.; Holloway, J. S.; Lefer, B.; Brown, S. S.; Thornton, J. A.

    2014-04-01

    Nitryl chloride (ClNO2) is produced at night by reactions of dinitrogen pentoxide (N2O5) on chloride containing surfaces. ClNO2 is photolyzed during the morning hours after sunrise to liberate highly reactive chlorine atoms (Cl·). This chemistry takes place primarily in polluted environments where the concentrations of N2O5 precursors (nitrogen oxide radicals and ozone) are high, though it likely occurs in remote regions at lower intensities. Recent field measurements have illustrated the potential importance of ClNO2 as a daytime Cl· source and a nighttime NOx reservoir. However, the fate of the Cl· and the overall impact of ClNO2 on regional photochemistry remain poorly constrained by measurements and models. To this end, we have incorporated ClNO2 production, photolysis, and subsequent Cl· reactions into an existing master chemical mechanism (MCM version 3.2) box model framework using observational constraints from the CalNex 2010 field study. Cl· reactions with a set of alkenes and alcohols, and the simplified multiphase chemistry of N2O5, ClNO2, HOCl, ClONO2, and Cl2, none of which are currently part of the MCM, have been added to the mechanism. The presence of ClNO2 produces significant changes to oxidants, ozone, and nitrogen oxide partitioning, relative to model runs excluding ClNO2 formation. From a nighttime maximum of 1.5 ppbv ClNO2, the daytime maximum Cl· concentration reaches 1 × 105 atoms cm-3 at 07:00 model time, reacting mostly with a large suite of volatile organic compounds (VOC) to produce 2.2 times more organic peroxy radicals in the morning than in the absence of ClNO2. In the presence of several ppbv of nitrogen oxide radicals (NOx = NO + NO2), these perturbations lead to similar enhancements in hydrogen oxide radicals (HOx = OH + HO2). Neglecting contributions from HONO, the total integrated daytime radical source is 17% larger when including ClNO2, which leads to a similar enhancement in integrated ozone production of 15%. Detectable

  7. Nigerian Journal of Basic and Applied Sciences vol. 16 No. 2 ...

    African Journals Online (AJOL)

    2008-12-02

    Dec 2, 2008 ... Ishola. O., Eneji, A.E. and Agboola, A.A (1998). Soil fertility changes under hedgerows of. Senna Siamea and leucaena leucocephala in Ayepe, South Western Nigeria. Global. J. Pure Applied Sciences, 4(2): 101-104. Lena, Q.M., Willie, H. and Arthur, H. (1997). Background concentrations of trace metals.

  8. Bulletin of the Chemical Society of Ethiopia - Vol 18, No 2 (2004)

    African Journals Online (AJOL)

    Distribution of trace elements in muscle and organs of Tilapia, Oreochromis niloticus, from lakes Awassa and Ziway, Ethiopia · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Aweke Kebede, Taddese Wondimu. http://dx.doi.org/10.4314/bcse.v18i2.61427 ...

  9. Bulletin of the Chemical Society of Ethiopia - Vol 14, No 2 (2000)

    African Journals Online (AJOL)

    Comparison of closed-pressurized and open-refluxed vessel digestion systems for trace elements in the residual fuel oil reference material (SRM 1634c) · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. T. Wondimu, W. Goessler, 99-113.

  10. Electronic state selectivity in dication-molecule single electron transfer reactions: NO(2+) + NO.

    Science.gov (United States)

    Parkes, Michael A; Lockyear, Jessica F; Schröder, Detlef; Roithová, Jana; Price, Stephen D

    2011-11-07

    The single-electron transfer reaction between NO(2+) and NO, which initially forms a pair of NO(+) ions, has been studied using a position-sensitive coincidence technique. The reactivity in this class of collision system, which involves the interaction of a dication with its neutral precursor, provides a sensitive test of recent ideas concerning electronic state selectivity in dicationic single-electron transfer reactions. In stark contrast to the recently observed single-electron transfer reactivity in the analogous CO(2)(2+)/CO(2) and O(2)(2+)/O(2) collision systems, electron transfer between NO(2+) and NO generates two product NO(+) ions which behave in an identical manner, whether the ions are formed from NO(2+) or NO. This observed behaviour is in excellent accord with the recently proposed rationalization of the state selectivity in dication-molecule SET reactions using simple propensity rules involving one-electron transitions. This journal is © the Owner Societies 2011

  11. CO and NO2 Selective Monitoring by ZnO-Based Sensors

    Directory of Open Access Journals (Sweden)

    Nicola Donato

    2013-07-01

    Full Text Available ZnO nanomaterials with different shapes were synthesized, characterized and tested in the selective monitoring of low concentration of CO and NO2 in air. ZnO nanoparticles (NPs and nanofibers (NFs were synthesized by a modified sol-gel method in supercritical conditions and electrospinning technique, respectively. CO and NO2 sensing tests have demonstrated that the annealing temperature and shape of zinc oxide nanomaterials are the key factors in modulating the electrical and sensing properties. Specifically, ZnO NPs annealed at high temperature (700 °C have been found sensitive to CO, while they displayed negligible response to NO2. The opposite behavior has been registered for the one-dimensional ZnO NFs annealed at medium temperature (400 °C. Due to their adaptable sensitivity/selectivity characteristics, the developed sensors show promising applications in dual air quality control systems for closed ambient such as automotive cabin, parking garage and tunnels.

  12. Combining Bayesian methods and aircraft observations to constrain the HO. + NO2 reaction rate

    Directory of Open Access Journals (Sweden)

    A. G. Carlton

    2012-01-01

    Full Text Available Tropospheric ozone is the third strongest greenhouse gas, and has the highest uncertainty in radiative forcing of the top five greenhouse gases. Throughout the troposphere, ozone is produced by radical oxidation of nitrogen oxides (NOx = NO + NO2. In the upper troposphere (8–10 km, current chemical transport models under-estimate nitrogen dioxide (NO2 observations. Improvements to simulated NOx production from lightning have increased NO2 predictions, but the predictions in the upper troposphere remain biased low. The upper troposphere has low temperatures (T 2 and radicals, is currently over-estimated by 22% in the upper troposphere. The results from this study suggest that the temperature sensitivity of nitric acid formation is lower than currently recommended. Since the formation of nitric acid removes nitrogen dioxide and radicals that drive the production of ozone, the revised reaction rate will affect ozone concentrations in upper troposphere impacting climate and air quality in the lower troposphere.

  13. A first proposal for a general description model of forensic traces

    Science.gov (United States)

    Lindauer, Ina; Schäler, Martin; Vielhauer, Claus; Saake, Gunter; Hildebrandt, Mario

    2012-06-01

    In recent years, the amount of digitally captured traces at crime scenes increased rapidly. There are various kinds of such traces, like pick marks on locks, latent fingerprints on various surfaces as well as different micro traces. Those traces are different from each other not only in kind but also in which information they provide. Every kind of trace has its own properties (e.g., minutiae for fingerprints, or raking traces for locks) but there are also large amounts of metadata which all traces have in common like location, time and other additional information in relation to crime scenes. For selected types of crime scene traces, type-specific databases already exist, such as the ViCLAS for sexual offences, the IBIS for ballistic forensics or the AFIS for fingerprints. These existing forensic databases strongly differ in the trace description models. For forensic experts it would be beneficial to work with only one database capable of handling all possible forensic traces acquired at a crime scene. This is especially the case when different kinds of traces are interrelated (e.g., fingerprints and ballistic marks on a bullet casing). Unfortunately, current research on interrelated traces as well as general forensic data models and structures is not mature enough to build such an encompassing forensic database. Nevertheless, recent advances in the field of contact-less scanning make it possible to acquire different kinds of traces with the same device. Therefore the data of these traces is structured similarly what simplifies the design of a general forensic data model for different kinds of traces. In this paper we introduce a first common description model for different forensic trace types. Furthermore, we apply for selected trace types from the well established database schema development process the phases of transferring expert knowledge in the corresponding forensic fields into an extendible, database-driven, generalised forensic description model. The

  14. Determination of the NO2 concentration and its distribution with different DOAS techniques - a study in the metropolitan area of Hong Kong

    Science.gov (United States)

    Horbanski, M.; Chan, K. L.; Pöhler, D.; Wenig, M. O.; Platt, U.

    2012-04-01

    In Hong Kong, like in other urban areas, nitrogen dioxide (NO2) emissions still remain one of the most problematic pollutions. Even though a lot of effort has already been made towards their reduction, concentrations are often much above the recommended limits. Therefore, the Hong Kong Environmental Protection Department continuously monitors the NO2 concentration levels. These stations only give in-situ information at a few fixed locations, which are unable to capture the strong spatial gradients that are present in urban areas. These gradients are mainly caused by differences in automobile traffic, the population densities and industries that are found in the individual city areas. The gradients are further enhanced by street canyon effects. Hence, it can be assumed that there are areas with much higher pollution compared to the values at the official measuring sites. At present the uncertainties about the spatial NO2 distribution place a limitation on the assessment of health risks and on the quality of chemical model calculations. We applied a new Cavity Enhanced (CE-) DOAS instrument to car based measurements in the city of Hong Kong for eight days in December 2010. Measurements on mobile platforms like cars give the opportunity to create a map of the NO2 for a whole city area with high spatial resolution. The CE-DOAS instrument is distinguished by its compact and robust setup. It directly measures NO2 by its optical absorption and therefore it does not have interferences with other trace gas species like O3 or NOy. This is a great advantage over other NO2 instruments (e.g. solid state detectors or chemiluminescence instruments which have such known problems). For our measurements a van travels along carefully selected tracks to give a representative coverage of the area of interest. The mobile measurements are corrected for the varying meteorological conditions and traffic variations during the different measurements by comparing them to a fixed measurement

  15. Potential reductions in ambient NO2 concentrations from meeting diesel vehicle emissions standards

    Science.gov (United States)

    von Schneidemesser, Erika; Kuik, Friderike; Mar, Kathleen A.; Butler, Tim

    2017-11-01

    Exceedances of the concentration limit value for ambient nitrogen dioxide (NO2) at roadside sites are an issue in many cities throughout Europe. This is linked to the emissions of light duty diesel vehicles which have on-road emissions that are far greater than the regulatory standards. These exceedances have substantial implications for human health and economic loss. This study explores the possible gains in ambient air quality if light duty diesel vehicles were able to meet the regulatory standards (including both emissions standards from Europe and the United States). We use two independent methods: a measurement-based and a model-based method. The city of Berlin is used as a case study. The measurement-based method used data from 16 monitoring stations throughout the city of Berlin to estimate annual average reductions in roadside NO2 of 9.0 to 23 µg m-3 and in urban background NO2 concentrations of 1.2 to 2.7 µg m-3. These ranges account for differences in fleet composition assumptions, and the stringency of the regulatory standard. The model simulations showed reductions in urban background NO2 of 2.0 µg m-3, and at the scale of the greater Berlin area of 1.6 to 2.0 µg m-3 depending on the setup of the simulation and resolution of the model. Similar results were found for other European cities. The similarities in results using the measurement- and model-based methods support our ability to draw robust conclusions that are not dependent on the assumptions behind either methodology. The results show the significant potential for NO2 reductions if regulatory standards for light duty diesel vehicles were to be met under real-world operating conditions. Such reductions could help improve air quality by reducing NO2 exceedances in urban areas, but also have broader implications for improvements in human health and other benefits.

  16. Spatial associations between socioeconomic groups and NO2 air pollution exposure within three large Canadian cities.

    Science.gov (United States)

    Pinault, Lauren; Crouse, Daniel; Jerrett, Michael; Brauer, Michael; Tjepkema, Michael

    2016-05-01

    Previous studies of environmental justice in Canadian cities have linked lower socioeconomic status to greater air pollution exposures at coarse geographic scales, (i.e., Census Tracts). However, studies that examine these associations at finer scales are less common, as are comparisons among cities. To assess differences in exposure to air pollution among socioeconomic groups, we assigned estimates of exposure to ambient nitrogen dioxide (NO2), a marker for traffic-related pollution, from city-wide land use regression models to respondents of the 2006 Canadian census long-form questionnaire in Toronto, Montreal, and Vancouver. Data were aggregated at a finer scale than in most previous studies (i.e., by Dissemination Area (DA), which includes approximately 400-700 persons). We developed simultaneous autoregressive (SAR) models, which account for spatial autocorrelation, to identify associations between NO2 exposure and indicators of social and material deprivation. In Canada's three largest cities, DAs with greater proportions of tenants and residents who do not speak either English or French were characterised by greater exposures to ambient NO2. We also observed positive associations between NO2 concentrations and indicators of social deprivation, including the proportion of persons living alone (in Toronto), and the proportion of persons who were unmarried/not in a common-law relationship (in Vancouver). Other common measures of deprivation (e.g., lone-parent families, unemployment) were not associated with NO2 exposures. DAs characterised by selected indicators of deprivation were associated with higher concentrations of ambient NO2 air pollution in the three largest cities in Canada. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  17. Next-Generation Aura/OMI NO2 and SO2 Products

    Science.gov (United States)

    Krotkov, Nickolay; Yang, Kai; Bucsela, Eric; Lamsal, Lok; Celarier, Edward; Swartz, William; Carn, Simon; Bhartia, Pawan; Gleason, James; Pickering, Ken; hide

    2011-01-01

    The measurement of both SO2 and NO2 gases are recognized as an essential component of atmospheric composition missions. We describe current capabilities and limitations of the operational Aura/OMI NO2 and SO2 data that have been used by a large number of researchers. Analyses of the data and validation studies have brought to light a number of areas in which these products can be expanded and improved. Major improvements for new NASA standard (SP) NO2 product include more accurate tropospheric and stratospheric column amounts, along with much improved error estimates and diagnostics. Our approach uses a monthly NO2 climatology based on the NASA Global Modeling Initiative (GMI) chemistry-transport model and takes advantage of OMI data from cloudy scenes to find clean areas where the contribution from the trap NO2 column is relatively small. We then use a new filtering, interpolation and smoothing techniques for separating the stratospheric and tropospheric components of NO2, minimizing the influence of a priori information. The new algorithm greatly improves the structure of stratospheric features relative to the original SP. For the next-generation OMI SO2 product we plan to implement operationally the offline iterative spectral fitting (ISF) algorithm and re-process the OMI Level-2 SO2 dataset using a priori SO2 and aerosol profiles, clouds, and surface reflectivity appropriate for observation conditions. This will improve the ability to detect and quantify weak tropospheric SO2 loadings. The new algorithm is validated using aircraft in-situ data during field campaigns in China (2005 and 2008) and in Maryland (Frostburg, 2010 and DISCOVER-AQ in July 2011). The height of the SO2 plumes will also be estimated for high SO2 loading cases (e.g., volcanic eruptions). The same SO2 algorithm will be applied to the data from OMPS sensor to be launched on NPP satellite later this year. The next-generation NO2 and SO2 products will provide critical information (e

  18. Reductions of NO2 detected from space during the 2008 Beijing Olympic Games

    Science.gov (United States)

    Mijling, B.; van der A, R. J.; Boersma, K. F.; Van Roozendael, M.; De Smedt, I.; Kelder, H. M.

    2009-07-01

    During the 2008 Olympic and Paralympic Games in Beijing (from 8 August to 17 September), local authorities enforced strong measures to reduce air pollution during the events. To evaluate the direct effect of these measures, we use the tropospheric NO2 column observations from the satellite instruments GOME-2 and OMI. We interpret these data against simulations from the regional chemistry transport model CHIMERE, based on a 2006 emission inventory, and find a reduction of NO2 concentrations of approximately 60% above Beijing during the Olympic period. The air quality measures were especially effective in the Beijing area, but also noticeable in surrounding cities of Tianjin (30% reduction) and Shijiazhuang (20% reduction).

  19. Sol-gel TiO2 films as NO2 gas sensors

    International Nuclear Information System (INIS)

    Georgieva, V; Gadjanova, V; Grechnikov, A; Donkov, N; Sendova-Vassileva, M; Kirilov, R; Stefanov, P

    2014-01-01

    TiO 2 films were prepared by a sol-gel technique with commercial TiO 2 powder as a source material (P25 Degussa AG). After a special treatment, printing paste was prepared. The TiO 2 layers were formed by means of drop-coating on Si-control wafers and on the Au-electrodes of quartz resonators. The surface morphology of the films was examined by scanning electron microscopy (SEM). Their structure was studied by Raman spectroscopy and the surface composition was determined by X-ray photoelectron spectroscopy (XPS). The layers had a grain-like surface morphology and consisted mainly of anatase TiO 2 phase. The sensitivity of the TiO 2 films to NO 2 was assessed by the quartz crystal microbalance (QCM) technique. To this end, the films were deposited on both sides of a 16-MHz QCM. The sensing characteristic of the TiO 2 -QCM structure was investigated by measuring the resonant frequency shift (ΔF) of the QCM due to the mass loading caused by NO 2 adsorption. The Sauerbrey equation was applied to establish the correlation between the QCM frequency changes measured after exposure to different NO 2 concentrations and the mass-loading of the QCM. The experiments were carried out in a dynamic mode on a special laboratory setup with complete control of the process parameters. The TiO 2 films were tested in the NO 2 concentration interval from 10 ppm to 5000 ppm. It was found that a TiO 2 loading of the QCM by 5.76 kHz corresponded to a system sensitive to NO 2 concentrations above 250 ppm. On the basis of the frequency-time characteristics (FTCs) measured, AF at different NO 2 concentrations was defined, the adsorption/desorption cycles were studied and the response and recovery times were estimated. The results obtained show that the process is reversible in the NO 2 interval investigated. The results further suggested that TiO 2 films prepared by a sol-gel method on a QCM can be used as a sensor element for NO 2 detection.

  20. Long-term changes of tropospheric NO2 over megacities derived from multiple satellite instruments

    Directory of Open Access Journals (Sweden)

    A. Hilboll

    2013-04-01

    Full Text Available Tropospheric NO2, a key pollutant in particular in cities, has been measured from space since the mid-1990s by the GOME, SCIAMACHY, OMI, and GOME-2 instruments. These data provide a unique global long-term dataset of tropospheric pollution. However, the observations differ in spatial resolution, local time of measurement, viewing geometry, and other details. All these factors can severely impact the retrieved NO2 columns. In this study, we present three ways to account for instrumental differences in trend analyses of the NO2 columns derived from satellite measurements, while preserving the individual instruments' spatial resolutions. For combining measurements from GOME and SCIAMACHY into one consistent time series, we develop a method to explicitly account for the instruments' difference in ground pixel size (40 × 320 km2 vs. 30 × 60 km2. This is especially important when analysing NO2 changes over small, localised sources like, e.g. megacities. The method is based on spatial averaging of the measured earthshine spectra and extraction of a spatial pattern of the resolution effect. Furthermore, two empirical corrections, which summarise all instrumental differences by including instrument-dependent offsets in a fitted trend function, are developed. These methods are applied to data from GOME and SCIAMACHY separately, to the combined time series, and to an extended dataset comprising also GOME-2 and OMI measurements. All approaches show consistent trends of tropospheric NO2 for a selection of areas on both regional and city scales, for the first time allowing consistent trend analysis of the full time series at high spatial resolution. Compared to previous studies, the longer study period leads to significantly reduced uncertainties. We show that measured tropospheric NO2 columns have been strongly increasing over China, the Middle East, and India, with values over east-central China tripling from 1996 to 2011. All parts of the developed world

  1. Digital Traces of Information Systems

    DEFF Research Database (Denmark)

    Hedman, Jonas; Srinivasan, Nikhil; Lindgren, Rikard

    2013-01-01

    In this paper, we point to the potential and implications of digital traces as novel data source in the study of contemporary activities and behaviors. We do this to raise awareness of IS researchers of such traces in increasingly complex sociomaterial practices. We develop a two-dimensional fram...

  2. Inter-comparison of stratospheric O3 and NO2 abundances retrieved from balloon borne direct sun observations and Envisat/SCIAMACHY limb measurements

    Directory of Open Access Journals (Sweden)

    A. Butz

    2006-01-01

    Full Text Available Stratospheric O3 and NO2 abundances measured by different remote sensing instruments are inter-compared: (1 Line-of-sight absorptions and vertical profiles inferred from solar spectra in the ultra-violet (UV, visible and infrared (IR wavelength ranges measured by the LPMA/DOAS (Limb Profile Monitor of the Atmosphere/Differential Optical Absorption Spectroscopy balloon payload during balloon ascent/descent and solar occultation are examined with respect to internal consistency. (2 The balloon borne stratospheric profiles of O3 and NO2 are compared to collocated space-borne skylight limb observations of the Envisat/SCIAMACHY satellite instrument. The trace gas profiles are retrieved from SCIAMACHY spectra using different algorithms developed at the Universities of Bremen and Heidelberg and at the Harvard-Smithsonian Center for Astrophysics. A comparison scheme is used that accounts for the spatial and temporal mismatch as well as differing photochemical conditions between the balloon and satellite borne measurements. It is found that the balloon borne measurements internally agree to within ±10% and ±20% for O3 and NO2, respectively, whereas the agreement with the satellite is ±20% for both gases in the 20 km to 30 km altitude range and in general worse below 20 km.

  3. Evaluation of reported NOx emission trends between 2005 and 2013 by assimilation of OMI-NO2 data into LOTOS-EUROS

    Science.gov (United States)

    Schaap, Martijn; Segers, Arjo; Curier, Lyana; Timmermans, Renske

    2016-04-01

    Consistent and long time series of remotely sensed trace gas levels may provide a useful tool to estimate surface emissions and emission trends. We use the OMI-NO2 product in conjunction with the LOTOS-EUROS CTM to estimate European emission trends through correction of the OMI-time series for meteorological variability as well as through assimilation using an ensemble kalman filter system (EnKF). The chemistry transport model captures a large fraction of the variability in NO2 columns at a synoptic timescale, although a seasonal signal in the bias between the modeled and retrieved column data remains. Prior to the assimilation, the OMI-NO2 data have been analyzed to establish the spatially variable temporal and spatial correlation lengths, required for the settings in the EnKF system. The assimilation run for 2005-2013 was performed using constant 2005 emissions to be able to quantify the emission change. The assimilation reduces the model-observation differences considerably. Significant negative trends of 2-3 % per year (as compared to 2005) were found in highly industrialized areas across Western Europe. The assimilation system also identifies the areas with major emission reductions in e.g. northern Spain as identified in earlier studies. Comparison of the trends derived from the assimilation and the data itself shows a high level of agreement, both the trends found in this way are smaller than those reported.

  4. Trace elements in sera from patients with visceral leishmaniasis

    International Nuclear Information System (INIS)

    Mukhopadhyay, R.; Bhattacharya, A.; Chakraborty, A.; Sudarshan, M.; Jal, P.K.; Chintalapudi, S.N.; Dutta, R.K.

    2000-01-01

    Trace elements are known to have pivotal role in human health and disease. Present investigation employed PIXE analysis to probe into the elemental profile of patients suffering from visceral Leishmaniasis. Remarkable alternations were observed in concentration of elements like Cl, K, Ca, Mn, Fe, Cu, Zn. The pattern of enhancement of elemental concentration corresponds to the progression of the disease. Additionally, our present data reflect probable correlation between alteration in trace elemental status and other pathological syndromes associated with Leishmaniasis. The possibility of considering trace elements as a diagnostic marker for a better understanding of the disease is discussed. (author)

  5. Trace elements in sera from patients with visceral leishmaniasis

    Energy Technology Data Exchange (ETDEWEB)

    Mukhopadhyay, R.; Bhattacharya, A. [Department of Zoology, Calcutta University, Calcutta (India); Chakraborty, A.; Sudarshan, M.; Jal, P.K.; Chintalapudi, S.N. [Inter University Consortium for DAE Facilities, Calcutta Centre 3/LB-8, Bidhan Nagar, Calcutta (India); Dutta, R.K. [Schonland Research Centre for Nuclear Sciences, University of Witwatersrand, Johannesburg (South Africa)

    2000-07-01

    Trace elements are known to have pivotal role in human health and disease. Present investigation employed PIXE analysis to probe into the elemental profile of patients suffering from visceral Leishmaniasis. Remarkable alternations were observed in concentration of elements like Cl, K, Ca, Mn, Fe, Cu, Zn. The pattern of enhancement of elemental concentration corresponds to the progression of the disease. Additionally, our present data reflect probable correlation between alteration in trace elemental status and other pathological syndromes associated with Leishmaniasis. The possibility of considering trace elements as a diagnostic marker for a better understanding of the disease is discussed. (author)

  6. Parentage analysis of Dongfang No.2, a hybrid of a female gametophyte clone of Laminaria japonica (Laminariales, Phaeophyta) and a male clone of L. longissima

    Science.gov (United States)

    Shi, Yuanyuan; Yang, Guanpin; Liao, Meijie; Li, Xiaojie; Cong, Yizhou; Qu, Shancun; Wang, Tongyong

    2008-05-01

    The cultivation of the first filial generation of monoploid gametophyte clones of different Laminaria species (hybrid Laminaria) is an effective way of utilizing heterozygous vigor (heterosis). A female gametophyte clone of L. japonica and a male gametophyte clone of L. longissima were hybridized, generating Dongfang No.2 hybrid Laminaria. The parentage of this hybrid Laminaria was determined using AFLP of total DNA, SNP of the ITS region of ribosomal RNA transcription unit and microsatellite DNA variation at two loci. In addition to 167 AFLP bands shared by Dongfang No.2, L. japonica and L. longissima, Dongfang No.2 hybrid Laminaria shared another 70 and 55 bands with L. japonica and L. longissima, respectively, which were obviously more than 11 bands shared by L. japonica and L. longissima. Dongfang No.2 held both ‘T’ and ‘C’ at position 847 of the ITS region, while ‘T’ at this position was specific for L. japonica and ‘C’ for L. longissima, respectively. Dongfang No.2 also held the microsatellite DNA alleles of two parents together at two microsatellite DNA marker loci. These observations clearly proved that Dongfang No.2 is a true hybrid of L. japonica and L. longissiuma. Unfortunately, the origin of the chloroplast of Dongfang No.2 was not determined based on the variation of RuBisCo spacer. More sequence variants of both ITS region and RuBisCo spacer were identified in Dongfang No.2 and most of them did not exist in either L. japonica or L. longissima. The unexpected variants may be due to the mutation of gametophyte clones occurring during their vegetative amplification.

  7. Low-limit detection of NO2 by longitudinal mode selection in a ...

    Indian Academy of Sciences (India)

    Abstract. The paper reports the pulsed laser-based photoacoustic (PA) spectroscopy of NO2 in a resonant PA cavity with special filters made of stainless steel. The PA cell along with special types of sound filters are designed and fabricated to excite only the second-order longitudinal mode inside the cavity. The second ...

  8. Retrieval of stratospheric O 3 and NO 2 vertical profiles using zenith ...

    Indian Academy of Sciences (India)

    An algorithm has been developed to retrieve vertical profiles of ozone (O3) and nitrogen dioxide (NO2) from ground-based measurements using the Chahine iteration method.This retrieval method has been checked using measured and recalculated slant column densities (SCDs)and they are found to be well matching.

  9. NO2inhalation causes tauopathy by disturbing the insulin signaling pathway.

    Science.gov (United States)

    Yan, Wei; Ku, Tingting; Yue, Huifeng; Li, Guangke; Sang, Nan

    2016-12-01

    Air pollution has been evidenced as a risk factor for neurodegenerative tauopathies. NO 2 , a primary component of air pollution, is negatively linked to neurodegenerative disorders, but its independent and direct association with tau lesion remains to be elucidated. Considering the fact that the insulin signaling pathway can be targeted by air pollutants and regulate tau function, this study focused on the role of insulin signaling in this NO 2 -induced tauopathy. Using a dynamic inhalation treatment, we demonstrated that exposure to NO 2 induced a disruption of insulin signaling in skeletal muscle, liver, and brain, with associated p38 MAPK and/or JNK activation. We also found that in parallel with these kinase signaling cascades, the compensatory hyperinsulinemia triggered by whole-body insulin resistance (IR) further attenuated the IRS-1/AKT/GSK-3β signaling pathway in the central nervous system, which consequently increased the phosphorylation of tau and reduced the expression of synaptic proteins that contributed to the development of the tau pathology. These findings provide new insight into the possible mechanisms involved in the etiopathogenesis of NO 2 -induced tauopathy, suggesting that the targeting of insulin signaling may be a promising therapeutic strategy to prevent this disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. CENRTC Project No. 2F3EOA, OCB A-372, acceptance test procedure

    International Nuclear Information System (INIS)

    Akerson, A.W.

    1995-01-01

    This test procedure provides the steps necessary to verify correct functional operation of controls, annunciators, alarms, protective relays and related systems impacted by CENRTC No. 2F3EOA, Microwave Transfer Trip Project, modification work performed under work package 6B-93-00038/M (CENRTC 2F3EOA MWTT OCB A-372 PACKAGE)

  11. Journal of Agriculture and Social Research (JASR) Vol. 8, No. 2, 2008

    African Journals Online (AJOL)

    8, No. 2, 2008. 147. Fig., 2 - Force Field Analysis of a General Problem. To do feasibility study based on this method, at first evaluator should determine driving and restraining forces, based on facilitating or hampering potential to gain AASs objectives. In next step, he/she should give each factor a score of between 1 and 5, ...

  12. Retrieval of stratospheric O3 and NO2 vertical profiles using zenith ...

    Indian Academy of Sciences (India)

    profiles of ozone (O3) and nitrogen dioxide (NO2) from ground-based measurements using the. Chahine iteration method. ... Ozone; nitrogen dioxide; vertical profile; total column density; air mass factor; solar zenith angle. J. Earth Syst. Sci. 115, No. .... SZA, initial guess profile, tropospheric pollution and the errors in the ...

  13. NO2-induced synthesis of nitrato-iron(III) porphyrin with diverse ...

    Indian Academy of Sciences (India)

    NO2-induced synthesis of nitrato-iron(III) porphyrin with diverse coordination mode and the formation of isoporphyrin. ‡. JAGANNATH BHUYANa and SABYASACHI SARKARb,∗. aDepartment of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India. bDepartment of Chemistry, Bengal Engineering and ...

  14. Editor's Note The current issue — Vol. 2. No.2, of the Contemporary ...

    African Journals Online (AJOL)

    Admin

    Editor's Note. The current issue — Vol. 2. No.2, of the Contemporary Journal of African Studies (CJAS), is the fourth in the series under this title, the successor to the Research Review of the Institute of ... to be found in many journal titles, some of which, in any case, are not on African Studies. ... Taking advantage of the re-.

  15. 15 CFR Supplement No. 2 to Part 754 - Unprocessed Western Red Cedar

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Unprocessed Western Red Cedar No. Supplement No. 2 to Part 754 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE EXPORT ADMINISTRATION REGULATIONS SHORT SUPPLY CONTROLS Pt. 754, Supp. 2...

  16. Journal of Agriculture and Social Research (JASR) Vol. 8, No. 2, 2008

    African Journals Online (AJOL)

    Journal of Agriculture and Social Research (JASR) Vol. 8, No. 2, 2008. 174. IMPACT OF HUMAN ACTIVITIES ON ECOSYSTEM IN RIVERS STATE, NIGERIA. G.E. OMOKHUA1* AND A.O. ... The 8 human economic activities were: farming, fishing, logging, charcoal/fuelwood collection, construction/urban development ...

  17. Journal of Agriculture and Social Research (JASR) Vol. 11, No. 2 ...

    African Journals Online (AJOL)

    kayo

    Journal of Agriculture and Social Research (JASR) Vol. 11, No. 2, 2011. EFFECTS OF AGE AND SAMPLING POSITION ON .... Where, LAV = Lowest axial value of wood property. UAV = Highest axial value of wood property .... This falls in line with recommendations of. Poku et al (2001) in a lesser-used species from Ghana.

  18. Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2015

    NARCIS (Netherlands)

    Krotkov, Nickolay A.; McLinden, Chris A.; Li, Can; Lamsal, Lok N.; Celarier, Edward A.; Marchenko, Sergey V.; Swartz, William H.; Bucsela, Eric J.; Joiner, Joanna; Duncan, Bryan N.; Boersma, Folkert; Veefkind, J.P.; Levelt, Pieternel F.; Fioletov, Vitali E.; Dickerson, Russell R.; He, Hao; Lu, Zifeng; Streets, David G.

    2016-01-01

    The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2) and sulfur dioxide (SO2), since October 2004. The data products from the same instrument provide

  19. Observation of slant column NO2 using the super-zoom mode of AURA-OMI

    Directory of Open Access Journals (Sweden)

    R. C. Cohen

    2011-09-01

    Full Text Available We retrieve slant column NO2 from the super-zoom mode of the Ozone Monitoring Instrument (OMI to explore its utility for understanding NOx emissions and variability. Slant column NO2 is operationally retrieved from OMI (Boersma et al., 2007; Bucsela et al., 2006 with a nadir footprint of 13 × 24 km2, the result of averaging eight detector elements on board the instrument. For 85 orbits in late 2004, OMI reported observations from individual "super-zoom" detector elements (spaced at 13 × 3 km2 at nadir. We assess the spatial response of these individual detector elements in-flight and determine an upper-bound on spatial resolution of 9 km, in good agreement with on-ground calibration (7 km FWHM. We determine the precision of the super-zoom mode to be 2.1 × 1015 molecules cm−2, approximately a factor of √8 lower than an identical retrieval at operational scale as expected if random noise dominates the uncertainty. We retrieve slant column NO2 over the Satpura power plant in India; Seoul, South Korea; Dubai, United Arab Emirates; and a set of large point sources on the Rihand Reservoir in India using differential optical absorption spectroscopy (DOAS. Over these sources, the super-zoom mode of OMI observes variation in slant column NO2 of up to 30 × the instrumental precision within one operational footprint.

  20. Stenhammer: Concerto for Piano and Orchestra No. 2 in D minor / Robert Layton

    Index Scriptorium Estoniae

    Layton, Robert

    1994-01-01

    Uuest heliplaadist "Stenhammer: Concerto for Piano and Orchestra No. 2 in D minor, Op. 23. Serenade in F, Op. 31. Florez och Blanzeflor, Op. 3... Munich Philharmonic Orchestra / Stig Westerberg; Serenade - selected comparison: Gothenburg SO, Järvi" (2/87) BIS CD 310

  1. 7 CFR 51.2078 - U.S. No. 2 Mixed.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. No. 2 Mixed. 51.2078 Section 51.2078 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

  2. 78 FR 69985 - Irish Potatoes Grown in Colorado; Decreased Assessment Rate for Area No. 2

    Science.gov (United States)

    2013-11-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE...), hereinafter referred to as the ``Act.'' The Department of Agriculture (USDA) is issuing this rule in... members of the Committee are producers and handlers of Colorado Area No. 2 potatoes. They are familiar...

  3. Visualization of NO2 emission sources using temporal and spatial pattern analysis in Asia

    Science.gov (United States)

    Schütt, A. M. N.; Kuhlmann, G.; Zhu, Y.; Lipkowitsch, I.; Wenig, M.

    2016-12-01

    Nitrogen dioxide (NO2) is an indicator for population density and level of development, but the contributions of the different emission sources to the overall concentrations remains mostly unknown. In order to allocate fractions of OMI NO2 to emission types, we investigate several temporal cycles and regional patterns.Our analysis is based on daily maps of tropospheric NO2 vertical column densities (VCDs) from the Ozone Monitoring Instrument (OMI). The data set is mapped to a high resolution grid by a histopolation algorithm. This algorithm is based on a continuous parabolic spline, producing more realistic smooth distributions while reproducing the measured OMI values when integrating over ground pixel areas.In the resulting sequence of zoom in maps, we analyze weekly and annual cycles for cities, countryside and highways in China, Japan and Korea Republic and look for patterns and trends and compare the derived results to emission sources in Middle Europe and North America. Due to increased heating in winter compared to summer and more traffic during the week than on Sundays, we dissociate traffic, heating and power plants and visualized maps with different sources. We will also look into the influence of emission control measures during big events like the Olympic Games 2008 and the World Expo 2010 as a possibility to confirm our classification of NO2 emission sources.

  4. African Journal of Neurological Sciences 2010 - Vol. 29, No 2 http ...

    African Journals Online (AJOL)

    29, No 2 http://ajns.paans.org. 3. CLINICAL STUDIES / ETUDE CLINIQUES. CONTRIBUTION DE LA BIOPSIE STEREOTAXIQUE DANS LA PRISE EN CHARGE DES TUMEURS. CEREBRALES: A PROPOS DE 283 CAS. CONTRIBUTION OF STEREOTAXIC BIOPSY IN THE MANAGEMENT OF BRAIN TUMORS: A PROPOS.

  5. Analysis on concentration variety characteristics of SO2/NO2 in Chengdu city, southwest China

    Science.gov (United States)

    Wang, C.; Xiao, T.; Luo, Q.; WU, L.

    2017-12-01

    SO2 and NO2, the important gaseous precursors of atmospheric fine particles, are closely related to urban air quality. Chengdu located in the western China, is the capital city of Sichuan province. Though Sichuan province is one of four heavily polluted areas in China, the air pollution research in Chengdu is in a relative lack, when compared to developed cities as Beijing, Guangzhou, etc. This paper, based on characteristics of SO2 and NO2 in Chengdu, shows that: the average concentration of SO2, NO2 was 25.29 (mainly in the rage 10-40 ), 64.41 (mainly in the range 30-80 ), respectively. There is a similar annual and seasonal variation for them, yet significant differences in diurnal variation. Except summer, the air condition in Chengdu is seriously affected by SO2 and NO2, while the latter plays a more significant role. Multiple regression has good fitting performance to the diurnal variation in Chengdu. The purification efficiency of precipitation in different magnitude is also discussed. Key words: Chengdu; Pollution gas; Variety characteristics Acknowledgements: This study was supported by Pollution program in Wenjiang District, National Natural Science Foundation of China Fund Project (91337215,41575066), National Science and Technology Support Program(2015BAC03B05),Special Fund for Meteorological Re-search in the Public Interest (GYHY201406015),National Key Basic Research Program (2013CB733206), and Risk Assessment System of Significant Climate Events in Tibet (14H046), Scientific Research Foundation of CUIT (CRF201606)

  6. Journal of Agriculture and Social Research (JASR) Vol. 8, No. 2, 2008

    African Journals Online (AJOL)

    communicable disease that can be totally eliminated by the provision of clean and safe drinking water. Dracunculiasis is one of the ... Journal of Agriculture and Social Research (JASR) Vol. 8, No. 2, 2008 impact on child survival in terms of failure of childcare, self-care, domestic tasks and income generation. (Nwosu et al.

  7. WORK AT BUILDING 504 (RESTAURANT NO 2) Temporary closure of UBS Bank branch

    CERN Multimedia

    1999-01-01

    Due to refurbishment work at Restaurant No. 2, over-the-counter banking services at the building's UBS bank branch will be suspended for two months. However, the Bancomat machines there will remain in operation. Any questions you may have can be dealt with at the UBS branch in the Main Building.Thank you in advance for your understanding.

  8. Highly sensitive NO2 sensor using brush-coated ZnO nanoparticles

    Science.gov (United States)

    Chandra, Lalit; Dwivedi, R.; Mishra, V. N.

    2017-10-01

    This work reports the sensing properties of a ZnO nanoparticle (NP) based gas sensor. A sol-gel method was used for the synthesis of ZnO nanoparticles, and a brush coating technique for applying these in a thick film over the gold electrode. The structural properties of the ZnO film so developed have been studied using energy dispersive x-ray spectroscopy (EDS), x-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM), revealing a hexagonal wurtzite structure having particle size of ~25 to ~110 nm and roughness of ~136.303 nm. The sensitivity of the sensor to NO2, H2, CO, ethanol and propanol gases in the temperature range from 150 to 350 °C has been tested. Among all these gases, sensitivity to NO2 was found to be highest, at around fifty times greater than the next highest sensitivity, for ethanol gas. The sensor’s response to NO2 gas has been measured at ~945.12%/ppt (parts per thousand), with fast response time and recovery time at operating temperature 280 °C. The obtained result has been discussed with the help of surface and subsurface adsorption and desorption of NO2 molecules at the available trap sites (oxygen ions) on the ZnO nanoparticle surface. This sensor also exhibits excellent repeatability.

  9. Nigerian Journal of Basic and Applied Sciences vol. 16 No. 2 ...

    African Journals Online (AJOL)

    2008-12-02

    Dec 2, 2008 ... Nigerian Journal of Basic and Applied Sciences vol. 16 No. 2 December 2008 243 - 247. 243. Analysis of Cowpea Production under the National Programme on ..... Elements of Applied Econometrics CARD,. Ibadan, Nigeria. Olukosi, J.O. and Ogunbgile, A. O. (1989). Introduction to Agricultural Production.

  10. Egyptian Journal of Medical Human Genetics - Vol 12, No 2 (2011)

    African Journals Online (AJOL)

    Egyptian Journal of Medical Human Genetics - Vol 12, No 2 (2011) ... Serum interferon-alpha level in first degree relatives of systemic lupus erythematosus patients: Correlation with autoantibodies titers · EMAIL FREE FULL TEXT EMAIL FREE FULL ... LB Salah, CB Salem, F B'Chir, K Bouraoui, F Broly, S Saguem, 183-186.

  11. Journal of Agriculture and Social Research (JASR) VOL. 8, No. 2 ...

    African Journals Online (AJOL)

    Journal of Agriculture and Social Research (JASR) VOL. 8, No. 2, 2008. ASSESSMENT OF THE ... This study examines the frequency of ICT tools usage by agricultural extension agents in Imo State, Nigeria. Data for the study .... from electronic media programme and some ADP materials. Data analysis was by the use of.

  12. Wastewater and Biomass Characterization for the Activated Sludge Model No. 2: Biological Phosphorus Removal

    DEFF Research Database (Denmark)

    Henze, Mogens; Gujer, W.; Mino, T.

    1995-01-01

    The characterization of wastewater and biomass in relation to the Activated Sludge Model No. 2 is described. A new fraction of organic fermentable matter is needed. Phosphate accumulating organisms and their structural compounds polyphosphate and polyhydroxyalkanoate have to be included...... in the biomass characterization. There is still a need for development of analytical methods for characterization of the various components....

  13. Combining Bayesian methods and aircraft observations to constrain the HO. + NO2 reaction rate

    Science.gov (United States)

    Tropospheric ozone is the third strongest greenhouse gas, and has the highest uncertainty in radiative forcing of the top five greenhouse gases. Throughout the troposphere, ozone is produced by radical oxidation of nitrogen oxides (NO,x =NO+NO2). In the uppe...

  14. Electronic structure of hexanitroferrates K2M[Fe(NO2)6] where M ...

    Indian Academy of Sciences (India)

    Administrator

    Detailed variable temperature Mössbauer, infrared, EXAFS spectroscopic measurements and variable temperature magnetic susceptibility experiments were carried out on. K2PbFe(NO2)6 to investigate the electronic structure and correlate it to the observed unusual magnetic hyperfine interaction in the system. All these ...

  15. 76 FR 56778 - Puerto Rico; Amendment No. 2 to Notice of a Major Disaster Declaration

    Science.gov (United States)

    2011-09-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency Puerto Rico; Amendment No. 2 to Notice of a Major Disaster... notice of a major disaster declaration for the Commonwealth of Puerto Rico (FEMA-4017-DR), dated August...

  16. 75 FR 77889 - Puerto Rico; Amendment No. 2 to Notice of a Major Disaster Declaration

    Science.gov (United States)

    2010-12-14

    ... SECURITY Federal Emergency Management Agency Puerto Rico; Amendment No. 2 to Notice of a Major Disaster... notice of a major disaster declaration for the Commonwealth of Puerto Rico (FEMA-1946-DR), dated October... disaster declaration for the Commonwealth of Puerto Rico is hereby amended to include the following areas...

  17. Journal of Agriculture and Social Research, Vol. 13, No.2, 2013 USE ...

    African Journals Online (AJOL)

    UCHE

    13, No.2, 2013. 68. USE OF INDIGENOUS TECHNOLOGY IN PROCESSING AND UTILIZATION OF. NON-TIMBER FOREST PRODUCT IN SOUTH-EASTERN .... Winnowing is carried out after sun-drying it involves the use of a stream of air to separate ... coconut as snacks in both urban and rural areas of southeastern.

  18. Journal of Agriculture and Social Research (JASR) Vol. 12, No. 2 ...

    African Journals Online (AJOL)

    Alikwe

    Journal of Agriculture and Social Research (JASR) Vol. 12, No. 2, 2012. 158. EFFECTS OF PARTIAL REPLACEMENT OF GROUNDNUT CAKE WITH FULL. FAT SOYA ON INDIGENOUS GROWER CHICKS. ALIKWE, PHILIP. C. N.. Livestock Production Tech Department,. Niger Delta University, Wilberforce Island, Bayelsa ...

  19. Nigerian Journal of Basic and Applied Sciences - Vol 24, No 2 (2016)

    African Journals Online (AJOL)

    Nigerian Journal of Basic and Applied Sciences - Vol 24, No 2 (2016). Journal Home ... J.O. Ehinmidu, 9-14. http://dx.doi.org/10.4314/njbas.v24i2.2 ... Angular Spectral Analysis and Lowpass Filtering of Aeromagnetic Data Over Western Parts of Bornu Basin of Nigeria · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  20. Measurement of atmospheric NO2 profile using three-wavelength dual-differential absorption lidar

    Science.gov (United States)

    Liu, Qiuwu; Chen, Yafeng; Wang, Jie; Huang, Jian; Hu, Shunxing

    2017-11-01

    Lidar instruments are efficient detectors of air pollutants such as nitrogen dioxide (NO2). However, the measurement errors are not negligible due to the influence of the aerosol in the atmosphere. We present a novel lidar for measuring tropospheric NO2 vertical profiles. For improving the received powers, the emitter unit consists of two pulsed pump laser - dye laser combination, and use three wavelengths of 448.10nm, 447.20nm and 446.60 nm corresponding to the strong, medium and weak absorption of NO2 respectively. The effects of aerosol on tropospheric NO2 measurements by three - wavelength (448.10 -447.20 -446.60 nm) dual differential absorption lidar (dual-DIAL) and conventional two - wave length (448.10- 446.60nm) differential absorption lidar (DIAL) are theoretical analyzed, and their system err are computer simulated. Experimental results show that the three - wavelength dual - DIAL method is more effective to reduce the effects of aerosol than the two - wavelength DIAL method, and its system error is no more than 4% without correcting the aerosol effect.

  1. Journal of Agriculture and Social Research, Vol. 13, No.2, 2013 ...

    African Journals Online (AJOL)

    MR-NWAOGWUGWU

    Journal of Agriculture and Social Research, Vol. 13, No.2, 2013. 88. (waste to wealth) and the likes. It was also indicated that youth associations donate fund for project implementation (mean = 3.24). Such funds may be raised through group efforts since mobilization of resources in most communities is a collective action.

  2. Worldwide biogenic soil NOx emissions inferred from OMI NO2 observations

    NARCIS (Netherlands)

    Vinken, G.C.M.; Boersma, K.F.; Maasakkers, J.D.; Adon, M.; Martin, R.V.

    2014-01-01

    Biogenic NOx emissions from soils are a large natural source with substantial uncertainties in global bottom-up estimates (ranging from 4 to 15 Tg N yr-1). We reduce this range in emission estimates, and present a top-down soil NOx emission inventory for 2005 based on retrieved tropospheric NO2

  3. Journal of Agriculture and Social Research (JASR) VOL. 8, No. 2 ...

    African Journals Online (AJOL)

    Journal of Agriculture and Social Research (JASR) VOL. 8, No. 2, 2008. IMPACT OF DEFORESTATION ON ECOSYSTEM: A CASE STUDY OF THE. FRESH WATER SWAMP FOREST IN ONNE, NIGER DELTA REGION, NIGERIA. G.E. OMOKHUA1* AND A.O. KOYEJO2. 1Department of Forestry and Wildlife Management.

  4. APEX (Air Pollution Exercise) Volume 7: Industrialist's Manual No. 2, People's Pulp Plant.

    Science.gov (United States)

    Environmental Protection Agency, Research Triangle Park, NC. Office of Manpower Development.

    The Industrialist's Manual No. 2, People's Pulp Plant is part of a set of 21 manuals (AA 001 009-001 029) used in APEX (Air Pollution Exercise), a computerized college and professional level "real world" game simulation of a community with urban and rural problems, industrial activities, and air pollution difficulties. The first two sections,…

  5. Tracing Geothermal Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Michael C. Adams; Greg Nash

    2004-03-01

    Geothermal water must be injected back into the reservoir after it has been used for power production. Injection is critical in maximizing the power production and lifetime of the reservoir. To use injectate effectively the direction and velocity of the injected water must be known or inferred. This information can be obtained by using chemical tracers to track the subsurface flow paths of the injected fluid. Tracers are chemical compounds that are added to the water as it is injected back into the reservoir. The hot production water is monitored for the presence of this tracer using the most sensitive analytic methods that are economically feasible. The amount and concentration pattern of the tracer revealed by this monitoring can be used to evaluate how effective the injection strategy is. However, the tracers must have properties that suite the environment that they will be used in. This requires careful consideration and testing of the tracer properties. In previous and parallel investigations we have developed tracers that are suitable from tracing liquid water. In this investigation, we developed tracers that can be used for steam and mixed water/steam environments. This work will improve the efficiency of injection management in geothermal fields, lowering the cost of energy production and increasing the power output of these systems.

  6. Constraints on ship NOx emissions in Europe using OMI NO2 observations

    Science.gov (United States)

    Vinken, G. C. M.; Boersma, K. F.

    2012-04-01

    About 90% of world trade is transported by oceangoing ships, and seaborne trade has been shown to have increased by about 5% per year in the past decade. Global ship traffic is currently not regulated under international treaties (e.g. Kyoto protocol) and ships are still allowed to burn low-grade bunker fuel. As a result, ships emit large quantities of nitrogen oxides (NOx = NO + NO2), important precursors for ozone (O3) and particulate matter formation. Previous studies indicated that the global NOx emissions from shipping are in the range 3.0-10.4 Tg N per year (15-30% of total global NOx emissions). Because most ships sail within 400 km of the coast, it is important to understand the contribution of ship emissions to atmospheric composition in the densely populated coastal regions. Chemistry Transport Models (CTMs), in combination with emission inventories, are used to simulate atmospheric concentrations of air pollutants to assess the impact of ship emissions. However, these bottom-up inventories, based on extrapolation of a few engine measurements and strong assumptions, suffer from large uncertainties. In this study we provide top-down constraints on ship NOx emissions in Europe using satellite observations of NO2 columns. We use the nested version of the GEOS-Chem model (0.5°-0.667°) to simulate tropospheric NO2 columns over Europe for the years 2005-2006, using our plume-in-grid treatment of ship NOx emissions. We improve the NO2 retrievals from the Ozone Monitoring Instrument (OMI v2.0) by replacing the coarse a priori (TM4) vertical NO2 profiles (2°-3°) with the high-resolution GEOS-Chem profiles. This ensures consistency between the retrievals and model simulations. GEOS-Chem simulations of tropospheric NO2 columns show remarkable quantitative agreement with the observed OMI columns over Europe (R2=0.89, RMS difference < 0.2-1015 molec. cm-2), providing confidence in the ability of the model to simulate NO2 pollution over the European mainland. We

  7. Land use patterns and SO2 and NO2 pollution in Ulaanbaatar, Mongolia.

    Science.gov (United States)

    Huang, Yu-Kai; Luvsan, Munkh-Erdene; Gombojav, Enkhjargal; Ochir, Chimedsuren; Bulgan, Jargal; Chan, Chang-Chuan

    2013-07-01

    We proposed to study spatial distribution and source contribution of SO2 and NO2 pollution in Ulaanbaatar, Mongolia. We collected 2-week ambient SO2 and NO2 concentration samples at 38 sites, which were classified by major sources of air pollution such as ger areas and/or major roads, in three seasons as warm (September, 2011), cold (November-December, 2011), and moderate (March, 2012) in Ulaanbaatar. The SO2 and NO2 concentrations were collected by Ogawa ambient air passive samplers and analyzed by ion chromatography and spectrophotometry methods, respectively. Stepwise regression models were used to estimate the contribution of emission proxies, such as the distance to major roads, ger areas, power plants, and city center, to the ambient concentrations of SO2 and NO2. We found that the SO2 and NO2 concentrations were significantly higher in the cold season than in the warm and moderate seasons at all 38 ambient sampling sites. The SO2 concentrations in 20 ger sites (46.60 ppb in the cold season and 17.82 ppb in the moderate season) were significantly higher than in 18 non-ger sites (23.35 ppb in the cold season and 12.53 ppb in the moderate season). The NO2 concentrations at 19 traffic/road sites (12.85 ppb in the warm season and 20.48 ppb in the moderate season) were significantly higher than those at 19 urban sites (7.60 ppb and 14.39 ppb in the moderate season). Multiple regression models show that SO2 concentrations decreased by 23% in the cold and 17% in the moderate seasons at 0.70 km from the ger areas, an average of all sampling sites, and by 29% in the moderate season at 4.83 km from the city center, an average of all sampling sites. Multiple regression models show that the NO2 concentrations at 4.83 km from the city center decreased by 38% in the warm and 29% in the moderate seasons. Our models also report that NO2 concentrations at 0.16 km from the main roads decreased by 15% and 9% in the warm and the moderate seasons, respectively, and by 16% in the

  8. Identifying and Tracing User Needs

    Science.gov (United States)

    To, C.; Tauer, E.

    2017-12-01

    Providing adequate tools to the user community hinges on reaching the specific goals and needs behind the intended application of the tool. While the approach of leveraging user-supplied inputs and use cases to identify those goals is not new, there frequently remains the challenge of tracing those use cases through to implementation in an efficient and manageable fashion. Processes can become overcomplicated very quickly, and additionally, explicitly mapping progress towards the achievement of the user demands can become overwhelming when hundreds of use-cases are at play. This presentation will discuss a demonstrated use-case approach that has achieved an initial success with a tool re-design and deployment, the means to apply use cases in the generation of a roadmap for future releases over time, and the ability to include and adjust to new user requirements and suggestions with minimal disruption to the traceability. It is hoped that the findings and lessons learned will help make use case employment easier for others seeking to create user-targeted capabilities.

  9. Examination of paints by trace element analysis.

    Science.gov (United States)

    Krishnan, S S

    1976-10-01

    Trace element analysis using neutron activation analysis is effective and valuable, particularly in the examination of white household paint. Although physical appearance and resin composition are generally similar in these paint samples, trace element composition provides an effective way of distinguishing among them. In the case of automobile paint samples, NAA serves as an important additional technique for discrimination. The technique is important when sample sizes are very small. The technique developed takes a few minutes for sample preparation, a few hours of irradiation time (during which the examiner's presence is not required), and then a few minutes for counting and obtaining quantitative multielement concentration patterns. A technician can easily handle 30 to 50 samples per day.

  10. Variable Mixed Orbital Character in the Photoelectron Angular Distribution of NO_{2}

    Science.gov (United States)

    Laws, Benjamin A.; Cavanagh, Steven J.; Lewis, Brenton R.; Gibson, Stephen T.

    2017-06-01

    NO_{2} a key component of photochemical smog and an important species in the Earth's atmosphere, is an example of a molecule which exhibits significant mixed orbital character in the HOMO. In photoelectron experiments the geometric properties of the parent anion orbital are reflected in the photoelectron angular distribution (PAD), an area of research that has benefited largely from the ability of velocity-map imaging (VMI) to simultaneously record both the energetic and angular information, with 100% collection efficiency. Photoelectron spectra of NO_{2}^{-}, taken over a range of wavelengths (355nm-520nm) with the ANU's VMI spectrometer, reveal an anomalous jump in the anisotropy parameter near threshold. Consequently, the orbital behavior of NO_{2}^{-} appears to be quite different near threshold compared to detachment at higher photon energies. This surprising effect is due to the Wigner Threshold law, which causes p orbital character to dominate the photodetachment cross-section near threshold, before the mixed s/d orbital character becomes significant at higher electron kinetic energies. By extending recent work on binary character models to form a more general expression, the variable mixed orbital character of NO_{2}^{-} is able to be described. This study provides the first multi-wavelength NO_{2} anisotropy data, which is shown to be in decent agreement with much earlier zero-core model predictions of the anisotropy parameter. K. J. Reed, A. H. Zimmerman, H. C. Andersen, and J. I. Brauman, J. Chem. Phys. 64, 1368, (1976). doi:10.1063/1.432404 D. Khuseynov, C. C. Blackstone, L. M. Culberson, and A. Sanov, J. Chem. Phys. 141, 124312, (2014). doi:10.1063/1.4896241 W. B. Clodius, R. M. Stehman, and S. B. Woo, Phys. Rev. A. 28, 760, (1983). doi:10.1103/PhysRevA.28.760 Research supported by the Australian Research Council Discovery Project Grant DP160102585

  11. Satellite observations and model simulations of tropospheric NO2 columns over south-eastern Europe

    Directory of Open Access Journals (Sweden)

    M. van Roozendael

    2009-08-01

    Full Text Available Satellite observations of nitrogen dioxide (NO2 tropospheric columns over south-eastern Europe are analyzed to study the characteristics of the spatial and temporal variability of pollution in the area. The interannual variability of the tropospheric NO2 columns is presented over urban, rural and industrial locations based on measurements from four satellite instruments, GOME/ERS-2, SCIAMACHY/Envisat, OMI/Aura and GOME-2/MetOp spanning a period of over twelve years. The consistency between the different datasets over the area is investigated. Two operational algorithms for the retrieval of tropospheric NO2 are considered, the one developed jointly by the Royal Netherlands Meteorological Institute and Belgian Institute for Space Astronomy and the one developed by the University of Bremen. The tropospheric NO2 columns for the area under study have been simulated for the period 1996–2001 with the Comprehensive Air Quality Model (CAMx and are compared with GOME measurements. Over urban and industrial locations the mean tropospheric NO2 columns range between 3 and 7.0×1015 molecules/cm2, showing a seasonal variability with a peak to peak amplitude of about 6.0×1015 molecules/cm2, while the background values over rural sites are close to 1.1×1015 molecules/cm2. Differences in the overpass time and spatial resolution of the different satellites, as well as differences in the algorithms, introduce significant differences in the estimated columns however the correlation between the different estimates is higher than 0.8. It is found that the model simulations reveal similar spatial patterns as the GOME observations, a result which is consistent with both algorithms. Although the model simulations show a mean bias of −0.1×1015 molecules/cm2 under clean conditions, the modeled temporal correlation of 0.5 is poor in absence of biogenic and biomass burning emissions.

  12. Radiation control in the core shroud replacement project of Fukushima-Daiichi NPS Unit no.2

    International Nuclear Information System (INIS)

    Kokubun, Yasunori; Haraguchi, Kazuyuki; Yoshizawa, Yuji; Yamada, Yasuo

    2000-01-01

    In Fukushima-Daiichi NPS Unit no.2, the core shroud replacement was made following that of Unit no.3. This project involves replacement of wide-ranging equipment, with the project extending over a long period of time. This was expected to increase the dose equivalent of workers. Accordingly, various measures to lower the dose equivalent were planned and implemented. We outline radiation controls implemented during the project period. The shroud replacement project was a preventive maintenance project which consisted of replacing the core shroud and other internals with those less susceptible to stress corrosion cracking. Problems related to radiation control during the replacement project of Unit no.3 the year before last were summarized. We studied, planned, and implemented measures to be reflected in the project for Unit no.2. This was done to lower the dose equivalent as much as possible while paying due attention to safety and economy. For radiation control during the project for Unit no.2, experiments with Unit no.3 were fully exploited and any effective measures taken at that time were adopted in this project. Problems pointed out after that project with Unit no.3 resulted in new or improved measures being taken with Unit no.2. Measures taken over from the project with Unit no.3; a. Daily analysis of difference between expected and actual dose equivalents b. Dose reduction measures, chemical decontamination, temporary shield, flushing, etc.; New or improved measures; a. Dose reduction measures: Mechanical removal of radiation sources, strengthening of shield, etc.; b. Automatic remote control system; c. Use of new protective devices. With measures implemented as described above, the dose equivalent during shroud replacement of Unit no.2 was reduced by about 30% when compared with that (11.5 persons · Sv) in the case of Unit no.3. Implemented radiation controls will be checked and reviewed in future for reflection in projects with other units. (author)

  13. Mobile mini-DOAS measurement of the outflow of NO2 and HCHO from Mexico City

    Directory of Open Access Journals (Sweden)

    L. Molina

    2009-08-01

    Full Text Available We here present the results from mobile measurements using two ground-based zenith viewing Differential Optical Absorption Spectroscopy (DOAS instruments. The measurement was performed in a cross-section of the plume from the Mexico City Metropolitan Area (MCMA on 10 March 2006 as part of the MILAGRO field campaign. The two instruments operated in the UV and the visible wavelength region respectively and have been used to derive the differential vertical columns of HCHO and NO2 above the measurement route. This is the first time the mobile mini-DOAS instrument has been able to measure HCHO, one of the chemically most important and interesting gases in the polluted urban atmosphere. Using a mass-averaged wind speed and wind direction from the WRF model the instantaneous flux of HCHO and NO2 has been calculated from the measurements and the results are compared to the CAMx chemical model. The calculated flux through the measured cross-section was 1.9 (1.5–2.2 kg/s of HCHO and 4.4 (4.0–5.0 kg/s of NO2 using the UV instrument and 3.66 (3.63–3.73 kg/s of NO2 using the visible light instrument. The modeled values from CAMx for the outflow of both NO2 and HCHO, 1.1 and 3.6 kg/s, respectively, show a reasonable agreement with the measurement derived fluxes.

  14. Estimation of NOx emissions from NO2 hotspots in polluted background using satellite observations

    Science.gov (United States)

    Liu, Fei; Beirle, Steffen; Zhang, Qiang; Wagner, Thomas

    2015-04-01

    Satellite observations have been widely used to study NOx emissions from power plants and cities, which are major NOx sources with large impacts on human health and climate. The quantification of NOx emissions from measured column densities of NO2 requires information on the NOx lifetime, which is typically gained from atmospheric chemistry models. But some recent studies determined the NOx lifetime from the satellite observations as well by analyzing the downwind plume evolution; however, this approach was so far only applied for strong isolated 'point sources' located in clean background, like Riyadh in Saudi Arabia. Here we present a modified method for the quantification of NOx emissions and corresponding atmospheric lifetimes based on OMI observations of NO2, together with ECMWF wind fields, but without further model input, for hot spots located in polluted background. We use the observed NO2 patterns under calm wind conditions as proxy for the spatial patterns of NOx emissions; by this approach, even complex source distributions can be treated realistically. From the change of the spatial patterns of NO2 at larger wind speeds (separately for different wind directions), the effective atmospheric lifetime is fitted. Emissions are derived from integrated NO2 columns above background by division by the corresponding lifetime. NOx lifetimes and emissions are estimated for 19 power plants and 50 cities across China and the US. The derived lifetimes are 3.3 ± 1.2 hours on average with extreme values of 0.9 to 7.7 hours. The resulting very short lifetimes for mountainous sites have been found to be uncertain due to the potentially inaccurate ECMWF wind data in mountainous regions. The derived NOx emissions show overall good agreement with bottom-up inventories.

  15. Effect of aerosols and NO2 concentration on ultraviolet actinic flux near Mexico City during MILAGRO: measurements and model calculations

    Directory of Open Access Journals (Sweden)

    C. A. Corr

    2013-01-01

    Full Text Available Urban air pollution absorbs and scatters solar ultraviolet (UV radiation, and thus has a potentially large effect on tropospheric photochemical rates. We present the first detailed comparison between actinic fluxes (AF in the wavelength range 330–420 nm measured in highly polluted conditions and simulated with the Tropospheric Ultraviolet-Visible (TUV model. Measurements were made during the MILAGRO campaign near Mexico City in March 2006, at a ground-based station near Mexico City (the T1 supersite and from the NSF/NCAR C-130 aircraft. At the surface, measured AF values are typically smaller than the model by up to 25% in the morning, 10% at noon, and 40% in the afternoon, for pollution-free and cloud-free conditions. When measurements of PBL height, NO2 concentration and aerosols optical properties are included in the model, the agreement improves to within ±10% in the morning and afternoon, and ±3% at noon. Based on daily averages, aerosols account for 68% and NO2 for 25% of AF reductions observed at the surface. Several overpasses from the C-130 aircraft provided the opportunity to examine the AF perturbations aloft, and also show better agreement with the model when aerosol and NO2 effects are included above and below the flight altitude. TUV model simulations show that the vertical structure of the actinic flux is sensitive to the choice of the aerosol single scattering albedo (SSA at UV wavelengths. Typically, aerosols enhance AF above the PBL and reduce AF near the surface. However, for highly scattering aerosols (SSA > 0.95, enhancements can penetrate well into the PBL, while for strongly absorbing aerosols (SSA < 0.6 reductions in AF are computed in the free troposphere as well as in the PBL. Additional measurements of the SSA at these wavelengths are needed to better constrain the effect of aerosols on the vertical structure of the AF.

  16. Effect of aerosols and NO2 concentration on ultraviolet actinic flux near Mexico City during MILAGRO: measurements and model calculations

    Science.gov (United States)

    Palancar, G. G.; Lefer, B. L.; Hall, S. R.; Shaw, W. J.; Corr, C. A.; Herndon, S. C.; Slusser, J. R.; Madronich, S.

    2013-01-01

    Urban air pollution absorbs and scatters solar ultraviolet (UV) radiation, and thus has a potentially large effect on tropospheric photochemical rates. We present the first detailed comparison between actinic fluxes (AF) in the wavelength range 330-420 nm measured in highly polluted conditions and simulated with the Tropospheric Ultraviolet-Visible (TUV) model. Measurements were made during the MILAGRO campaign near Mexico City in March 2006, at a ground-based station near Mexico City (the T1 supersite) and from the NSF/NCAR C-130 aircraft. At the surface, measured AF values are typically smaller than the model by up to 25% in the morning, 10% at noon, and 40% in the afternoon, for pollution-free and cloud-free conditions. When measurements of PBL height, NO2 concentration and aerosols optical properties are included in the model, the agreement improves to within ±10% in the morning and afternoon, and ±3% at noon. Based on daily averages, aerosols account for 68% and NO2 for 25% of AF reductions observed at the surface. Several overpasses from the C-130 aircraft provided the opportunity to examine the AF perturbations aloft, and also show better agreement with the model when aerosol and NO2 effects are included above and below the flight altitude. TUV model simulations show that the vertical structure of the actinic flux is sensitive to the choice of the aerosol single scattering albedo (SSA) at UV wavelengths. Typically, aerosols enhance AF above the PBL and reduce AF near the surface. However, for highly scattering aerosols (SSA > 0.95), enhancements can penetrate well into the PBL, while for strongly absorbing aerosols (SSA < 0.6) reductions in AF are computed in the free troposphere as well as in the PBL. Additional measurements of the SSA at these wavelengths are needed to better constrain the effect of aerosols on the vertical structure of the AF.

  17. Measurement of NO2 pollutant sorption of various trees, shrubs and ground cover plants using gas NO2 labelled 15N

    International Nuclear Information System (INIS)

    Nasrullah, Nizar; Wungkar, Marietje; Gunawan, Andi; Gandanegara, Soertini; Suharsono, Heny

    2000-01-01

    The objective of this study is to measure the NO 2 pollutant sorption of various trees, shrubs and ground cover plants. 32 species of trees, 64 speceis of shrubs and 13 species of ground cover plants were exposed to 3 ppm (v / v) N- 15 O 2 in a gas chamber for 60 minutes. Experiment consisted of 2 replicates. The environment conditions in the chamber were set at 30 o C, 1000 lux, and initial relative humidity 60 %. After gas treatment, plants parts were separated into leaves, stems and roots, than dried in 70 o C for 48 hours and then weighed. After weighing, those plants parts were ground to a pine powder. After kjendhal digestion, N total content of plants were analyzed by distillation method. 15 N content of plant samples were analyzed by emission spectrometer ( Yasco, N-151). The amount of N-15 absorbed by plant was the total content of 15 N in the whole plants ( leaves, stem and root ) per gram dry weight of leaves. The amount of 15 N absorbed by plants varied among investigated plants. 15 N sorption of trees are in the range 0.28 - 68.31μg/g. The sorption of shrubs and ground cover plants varied in 1.97 - 100.02 μg/g and 2.38 - 24.06μg/g, respectively. According to the amount of 15 N sorption , the plants were divided into 3 groups of sorption level, high ( > 30.0μg/g), moderate ( 15 - 30 μg/g ), and low sorption level ( 15 μg/g). Results showed that among of 32 investigated trees, 64 shrubs and 13 ground cover plant, 4 species of trees and 13 species of shrubs performed a high sorption level and no one of ground cover plants performed a high sorption level. The species of trees and 15 species of shrubs that mention above are recommended to use as an element of landscape which to be functioned to reduce NO 2 atmospheric pollutant

  18. Photoenhanced uptakes of NO2 by indoor surfaces: A new HONO source

    Science.gov (United States)

    Gligorovski, S.; Bartolomei, V.; Soergel, M.; Gomez Alvarez, E.; Zetzsch, C.; Wortham, H.

    2012-12-01

    Nitrous acid (HONO) is a known household pollutant that can lead to human respiratory tract irritation. HONO acts as the nitrosating agent, e.g. by the formation of the so-called third-hand smoke after wall reactions of HONO with nicotine (1). HONO can be generated indoors directly during combustion processes or indirectly via heterogeneous NO2 reactions with adsorbed water on diverse surfaces (2). Recently a new source was identified as another path of HONO formation in the troposphere (3). Namely, the light-induced heterogeneous reaction of NO2 with adsorbed organics (known as photosensitizers) on various surfaces such as roads, buildings, rocks or plants leads to enhanced HONO production. The detected values of HONO indoors vary in the range between 2 and 25 parts per billion (ppb). However, like outdoors, the processes leading to HONO formation indoors are not completely understood (4). Indoor photolysis radiation sources include exterior sunlight (λ>350 nm) that enters typically through the windows and indoor illumination sources, i.e., rare gas/mercury fluorescent light bulbs and tungsten and tungsten/halogen light bulbs among others. The present work is showing the importance of indoor sources of HONO recently identified or postulated. We have tested a number of common household chemical agents commonly used for cleaning purposes or coatings of domestic surfaces to better identify different indoor HONO sources. We used a heterogeneous flow tube technique to test the HONO production potentials of these household chemical agents under different experimental conditions, namely with and without light and at different relative humidity levels and different NO2 concentrations. We report uptake kinetics measurements of the heterogeneous reaction of gas phase NO2 with lacquer and paint coated on the walls of the reactor. The flow tube was irradiated with four near-ultraviolet (UV) emitting lamps (range of wavelengths 300-420nm). We observed that the heterogeneous

  19. Quantifying the contribution of individual vehicles to NO2 pollution in an urban area

    Science.gov (United States)

    Pöhler, Denis; Kanatschnig, Florian; Horbanski, Martin; Friedrich, Axel; Lampel, Johannes; Platt, Ulrich

    2015-04-01

    Nitrogen Dioxide (NOx) emissions by road vehicles are the mayor contributor for poor air quality in urban areas. High NOx concentrations, and especially NO2, are typically the most problematic pollutant in mega and other cities. However emissions vary significantly depending on the type of vehicle and its engine, the age and condition of the vehicle, driving properties and many more. Even if data of the manufacturer exists how much NOx different vehicle types emit, reliable data under real driving conditions are rare and often missing. Especially data showing the degree to which different cars contribute to observed NOx levels are missing. Significant reduction of NOx concentrations can be achieved by identifying the strong emitting vehicles and excluding / replacing these. As this is only a small amount of vehicles (typically less than 10% of the vehicles make 90% of the emissions), such a small investment can significantly improve air quality. In order to perform measurements of NOx we applied a high speed NO2 CE-DOAS (Cavity-Enhanced DOAS) instrument in a car which was modified for this application. It measured directly the NO2 concentration behind followed vehicles while driving, with a time resolution of 2 s and an accuracy of ~1ppb. Even if such observations depend on many parameters like mixing-in of ambient air, distance, solar radiation, ozone concentration, background concentration etc., it delivers valuable data under real driving conditions. The instrument was applied in the city of Mainz, Germany to investigate within 7 days (March / April 2014) the NOx emission of 728 vehicles and to quantify the main emitters. Therefore the measured NO2 concentration in comparison to the background concentrations was quantified. Observed vehicles were separated in 4 categories: cars, busses, trucks, and motorcycles. We observed NO2 levels from a few ppb (within the background variation) up to 7000ppb NO2 above the background level. Strong variations within the same

  20. Trace formulae for arithmetical systems

    International Nuclear Information System (INIS)

    Bogomolny, E.B.; Georgeot, B.; Giannoni, M.J.; Schmit, C.

    1992-09-01

    For quantum problems on the pseudo-sphere generated by arithmetic groups there exist special trace formulae, called trace formulae for Hecke operators, which permit the reconstruction of wave functions from the knowledge of periodic orbits. After a short discussion of this subject, the Hecke operators trace formulae are presented for the Dirichlet problem on the modular billiard, which is a prototype of arithmetical systems. The results of numerical computations for these semiclassical type relations are in good agreement with the directly computed eigenfunctions. (author) 23 refs.; 2 figs

  1. Synthesis of 3,4,5-Trisubstituted Isoxazoles from Morita-Baylis-Hillman Acetates by an NaNO2 /I2 -Mediated Domino Reaction.

    Science.gov (United States)

    Dighe, Shashikant U; Mukhopadhyay, Sushobhan; Kolle, Shivalinga; Kanojiya, Sanjeev; Batra, Sanjay

    2015-09-07

    An efficient NaNO2 /I2 -mediated one-pot transformation of Morita-Baylis-Hillman (MBH) acetates into alkyl 3-nitro-5-(aryl/alkyl)isoxazole-4-carboxylates is described. In a cascade event, initial Michael addition of NaNO2 to the MBH acetate furnishes the allylnitro intermediate which undergoes I2 -catalyzed oxidative α-CH nitration of the nitromethyl subunit followed by [3+2] cycloaddition to afford the title compounds. Structural elaborations of these highly substituted isoxazoles by SN Ar reactions and hydrogenolysis allows access to useful products. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Global inventory of nitrogen oxide emissions constrained by space-based observations of NO2 columns

    Science.gov (United States)

    Martin, Randall V.; Jacob, Daniel J.; Chance, Kelly; Kurosu, Thomas P.; Palmer, Paul I.; Evans, Mathew J.

    2003-09-01

    We use tropospheric NO2 columns from the Global Ozone Monitoring Experiment (GOME) satellite instrument to derive top-down constraints on emissions of nitrogen oxides (NOx ≡ NO + NO2), and combine these with a priori information from a bottom-up emission inventory (with error weighting) to achieve an optimized a posteriori estimate of the global distribution of surface NOx emissions. Our GOME NO2 retrieval improves on previous work by accounting for scattering and absorption of radiation by aerosols; the effect on the air mass factor (AMF) ranges from +10 to -40% depending on the region. Our AMF also includes local information on relative vertical profiles (shape factors) of NO2 from a global 3-D chemical transport model (GEOS-CHEM); assumption of a globally uniform shape factor, as in most previous retrievals, would introduce regional biases of up to 40% over industrial regions and a factor of 2 over remote regions. We derive a top-down NOx emission inventory from the GOME data by using the local GEOS-CHEM relationship between NO2 columns and NOx emissions. The resulting NOx emissions for industrial regions are aseasonal, despite large seasonal variation in NO2 columns, providing confidence in the method. Top-down errors in monthly NOx emissions are comparable with bottom-up errors over source regions. Annual global a posteriori errors are half of a priori errors. Our global a posteriori estimate for annual land surface NOx emissions (37.7 Tg N yr-1) agrees closely with the GEIA-based a priori (36.4) and with the EDGAR 3.0 bottom-up inventory (36.6), but there are significant regional differences. A posteriori NOx emissions are higher by 50-100% in the Po Valley, Tehran, and Riyadh urban areas, and by 25-35% in Japan and South Africa. Biomass burning emissions from India, central Africa, and Brazil are lower by up to 50%; soil NOx emissions are appreciably higher in the western United States, the Sahel, and southern Europe.

  3. Geometry-invariant GRIN lens: finite ray tracing.

    Science.gov (United States)

    Bahrami, Mehdi; Goncharov, Alexander V

    2014-11-17

    The refractive index distribution of the geometry-invariant gradient refractive index lens (GIGL) model is derived as a function of Cartesian coordinates. The adjustable external geometry of the GIGL model aims to mimic the shape of the human and animal crystalline lens. The refractive index distribution is based on an adjustable power-law profile, which provides additional flexibility of the model. An analytical method for layer-by-layer finite ray tracing through the GIGL model is developed and used to calculate aberrations of the GIGL model. The result of the finite ray tracing aberrations of the GIGL model are compared to those obtained with paraxial ray tracing. The derived analytical expression for the refractive index distribution can be employed in the reconstruction processes of the eye using the conventional ray tracing methods. The layer-by-layer finite ray tracing approach would be an asset in ray tracing through a modified GIGL model, where the refractive index distribution cannot be described analytically. Using the layer-by-layer finite ray-tracing method, the potential of the GIGL model in representing continuous as well as shell-like layered structures is illustrated and the results for both cases are presented and analysed.

  4. Relationships between lichen community composition and concentrations of NO2 and NH3

    International Nuclear Information System (INIS)

    Gadsdon, Sally R.; Dagley, Jeremy R.; Wolseley, Patricia A.; Power, Sally A.

    2010-01-01

    The relationship between different features of lichen communities in Quercus robur canopies and environmental variables, including concentrations of NO 2 and NH 3 was investigated. NO 2 concentration was the most significant variable, it was positively correlated with the proportion of lichen cover comprising nitrophytes and negatively correlated with total lichen cover. None of the lichen community features were correlated with NH 3 concentrations, which were relatively low across the site. Since nitrophytes and nitrophobes are likely to react in opposite directions to nitrogenous compounds, total lichen cover is not a suitable indicator for these pollutants. It is, therefore, suggested that the proportion of lichen cover comprising nitrophytes may be a suitable simple indicator of air quality, particularly in locations where the pollution climate is dominated by oxides of nitrogen. - Response of lichen communities to nitrogenous pollutants.

  5. Compliance with Operational Circular No. 2 on conditions of access to the fenced CERN sites

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The purpose of Operational Circular No. 2 is to contribute to the protection of people and property by defining the conditions of access to the Organization's fenced sites. However, recently, the services concerned have noted a significant increase in the instances of non-compliance with those conditions that cannot be tolerated, for example: use of CERN access cards by people, other than the cardholders themselves, in order to gain access to facilities without having attended the required safety course; speeding, particularly on Route Gregory and Route Weisskopf; driving in and out of the site on the wrong side of the road; parking on spaces set aside for the disabled; nuisance parking, especially in the proximity of the Restaurants; the dumping of wrecked vehicles. As the aforementioned instances of non-compliance can lead to dangerous situations, the Organization reserves the right to apply the penalties provided for under paragraph 26 of Operational Circular No. 2, namely to refuse access to the site...

  6. REMINDER - Compliance with Operational Circular No. 2 on conditions of access to the fenced CERN sites

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The purpose of Operational Circular No. 2 is to contribute to the protection of people and property by defining the conditions of access to the Organization's fenced sites. However, recently, the services concerned have noted a significant increase in the instances of non-compliance with those conditions that cannot be tolerated, for example: use of CERN access cards by people, other than the cardholders themselves, in order to gain access to facilities without having attended the required safety course; speeding, particularly on Route Gregory and Route Weisskopf; driving in and out of the site on the wrong side of the road; parking on spaces set aside for the disabled; nuisance parking, especially in the proximity of the Restaurants; the dumping of wrecked vehicles. As the aforementioned instances of non-compliance can lead to dangerous situations, the Organization reserves the right to apply the penalties provided for under paragraph 26 of Operational Circular No. 2, namely to refuse access to the site ...

  7. Two-photon photodissociation dynamics of state-selected NO2

    Science.gov (United States)

    Bigio, Laurence; Grant, Edward R.

    1987-07-01

    Quantum states of NO2 are selected and then photodissociated by resonant two-photon photoexcitation. The details of the photolysis and the optical-UV double-resonance (OUDR) spectroscopy are discussed, and results are presented for: (1) observations of the product state selected two-photon photodissociation cross section of NO2 near the O(1D) threshold, (2) the dynamics of NO production as a function of features selected in the photodissociation spectrum, (3) N labeling of relevant features by OUDR spectroscopy, and (4) estimation of the O(1D)/O(3P) branching ratio. A qualitative connection is established between the present observations and a new theoretical approach developed by Balint-Kurti et al. (1985) to account specifically for electronic degrees of freedom in state-to-state photodissociation.

  8. Start-up tests of Kashiwazakikariwa Nuclear Power Station Unit No.2 and No.5

    International Nuclear Information System (INIS)

    Fueki, Kensuke; Aoki, Shiro; Tanaka, Yasuhisa; Yahagi, Kimitoshi

    1991-01-01

    The Kashiwazakikariwa Nuclear Power Station Units No.5 and No.2 started commercial operation on April 10 and September 28 of 1990 respectively. As the result of the application of the First and Second LWR Improvement and Standardization Program, the plants were designed aiming at improvement of reliability, operation, and maintenance while maintaining safety. Construction of the plants took 6.5 to 7 years for completion, during which period the last 10 months were spent for the start up tests program. Start up tests were carried out under deliberate management to assure that the plants can operate safely and steadily at the prescribed operating points, and the schedules and tests item modifications adopted in Unit No.2 and No.5 were verified under the start up tests program. (author)

  9. Novel application of satellite and in-situ measurements to map surface-level NO2 in the Great Lakes region

    Directory of Open Access Journals (Sweden)

    C. Mihele

    2011-11-01

    Full Text Available Ozone Monitoring Instrument (OMI tropospheric NO2 vertical column density data were used in conjunction with in-situ NO2 concentrations collected by permanently installed monitoring stations to infer 24 h surface-level NO2 concentrations at 0.1° (~11 km resolution. The region examined included rural and suburban areas, and the highly industrialised area of Windsor, Ontario, which is situated directly across the US-Canada border from Detroit, MI. Photolytic NO2 monitors were collocated with standard NO2 monitors to provide qualitative data regarding NOz interference during the campaign. The accuracy of the OMI-inferred concentrations was tested using two-week integrative NO2 measurements collected with passive monitors at 18 locations, approximating a 15 km grid across the region, for 7 consecutive two-week periods. When compared with these passive results, satellite-inferred concentrations showed an 18% positive bias. The correlation of the passive monitor and OMI-inferred concentrations (R=0.69, n=115 was stronger than that for the passive monitor concentrations and OMI column densities (R=0.52, indicating that using a sparse network of monitoring sites to estimate concentrations improves the direct utility of the OMI observations. OMI-inferred concentrations were then calculated for four years to show an overall declining trend in surface NO2 concentrations in the region. Additionally, by separating OMI-inferred surface concentrations by wind direction, clear patterns in emissions and affected down-wind regions, in particular around the US-Canada border, were revealed.

  10. Limb-Nadir Matching Using Non-Coincident NO2 Observations: Proof of Concept and the OMI-minus-OSIRIS Prototype Product

    Science.gov (United States)

    Adams, Cristen; Normand, Elise N.; Mclinden, Chris A.; Bourassa, Adam E.; Lloyd, Nicholas D.; Degenstein, Douglas A.; Krotkov, Nickolay A.; Rivas, Maria Belmonte; Boersma, K. Folkert; Eskes, Henk

    2016-01-01

    A variant of the limb-nadir matching technique for deriving tropospheric NO2 columns is presented in which the stratospheric component of the NO2 slant column density (SCD) measured by the Ozone Monitoring Instrument (OMI) is removed using non-coincident profiles from the Optical Spectrograph and InfraRed Imaging System (OSIRIS). In order to correct their mismatch in local time and the diurnal variation of stratospheric NO2, OSIRIS profiles, which were measured just after sunrise, were mapped to the local time of OMI observations using a photochemical boxmodel. Following the profile time adjustment, OSIRIS NO2 stratospheric vertical column densities (VCDs) were calculated. For profiles that did not reach down to the tropopause, VCDs were adjusted using the photochemical model. Using air mass factors from the OMI Standard Product (SP), a new tropospheric NO2 VCD product - referred to as OMI-minus-OSIRIS (OmO) - was generated through limb-nadir matching. To accomplish this, the OMI total SCDs were scaled using correction factors derived from the next-generation SCDs that improve upon the spectral fitting used for the current operational products. One year, 2008, of OmO was generated for 60 deg S to 60 deg N and a cursory evaluation was performed. The OmO product was found to capture the main features of tropospheric NO2, including a background value of about 0.3 x 10(exp 15) molecules per sq cm over the tropical Pacific and values comparable to the OMI operational products over anthropogenic source areas. While additional study is required, these results suggest that a limb-nadir matching approach is feasible for the removal of stratospheric NO2 measured by a polar orbiter from a nadir-viewing instrument in a geostationary orbit such as Tropospheric Emissions: Monitoring of Pollution (TEMPO) or Sentinel-4.

  11. Trace elements induce predominance among methanogenic activity in anaerobic digestion

    Directory of Open Access Journals (Sweden)

    Babett Wintsche

    2016-12-01

    Full Text Available Trace elements play an essential role in all organisms due to their functions in enzyme complexes. In anaerobic digesters, control and supplementation of trace elements lead to stable and more efficient methane production processes while trace element deficits cause process imbalances. However, the underlying metabolic mechanisms and the adaptation of the affected microbial communities to such deficits are not yet fully understood. Here, we investigated the microbial community dynamics and resulting process changes induced by trace element deprivation. Two identical lab-scale continuous stirred tank reactors fed with distiller’s grains and supplemented with trace elements (cobalt, molybdenum, nickel, tungsten and a commercial iron additive were operated in parallel. After 72 weeks of identical operation, the feeding regime of one reactor was changed by omitting trace element supplements and reducing the amount of iron additive. Both reactors were operated for further 21 weeks. Various process parameters (biogas production and composition, total solids and volatile solids, trace element concentration, volatile fatty acids, total ammonium nitrogen, total organic acids/alkalinity ratio, and pH and the composition and activity of the microbial communities were monitored over the total experimental time. While the methane yield remained stable, the concentrations of hydrogen sulfide, total ammonia nitrogen, and acetate increased in the trace element-depleted reactor compared to the well-supplied control reactor. Methanosarcina and Methanoculleus dominated the methanogenic communities in both reactors. However, the activity ratio of these two genera was shown to depend on trace element supplementation explainable by different trace element requirements of their energy conservation systems. Methanosarcina dominated the well-supplied anaerobic digester, pointing to acetoclastic methanogenesis as the dominant methanogenic pathway. Under trace element

  12. IDEA papers no 2; Les cahiers d'I.D.E.A. n.2

    Energy Technology Data Exchange (ETDEWEB)

    Cassou, O

    2002-09-01

    The Information network on the Economic Development in Aquitaine (IDEA) aims to collect and spread the environmental information concerning the Aquitaine, in order to implement an observatory of the regional environment and of the sustainable development. The IDEA paper no. 2 is devoted to the IDEA missions and their cooperation with ''Alliance pour la qualite et la performance''. This association groups actors for the development and the promotion of the quality. (A.L.B.)

  13. African Journal of Neurological Sciences 2012 - Vol. 31, No 2 http ...

    African Journals Online (AJOL)

    AJNS WEBMASTERS

    African Journal of Neurological Sciences. 2012 - Vol. 31, No 2 ... différences sur le plan clinique, épidémiologique, immunologique et anatomopathologique entre SEP et. NMO [24]. Le traitement de NMO ... Les infections virales et bactériennes précédant ou accompagnant la NMO sont un phénomène connu. Le syndrome ...

  14. Kinetics of the reaction of CH3O2 radicals with NO2

    DEFF Research Database (Denmark)

    Wallington, T.J.; Nielsen, O.J.; Sehested, K.

    1999-01-01

    The kinetics of the gas-phase reaction of CH3O2 radicals with NO2 were studied at 295 K in 0.5-14 arm of SF6 diluent using pulse radiolysis combined with time-resolved UV-VIS spectroscopy. Rate data were obtained by following the loss of CH3O2 using a monitoring wavelength of 260 nm. The results...

  15. Indoor NO2 air pollution and lung function of professional cooks.

    Science.gov (United States)

    Arbex, M A; Martins, L C; Pereira, L A A; Negrini, F; Cardoso, A A; Melchert, W R; Arbex, R F; Saldiva, P H N; Zanobetti, A; Braga, A L F

    2007-04-01

    Studies of cooking-generated NO2 effects are rare in occupational epidemiology. In the present study, we evaluated the lung function of professional cooks exposed to NO2 in hospital kitchens. We performed spirometry in 37 cooks working in four hospital kitchens and estimated the predicted FVC, FEV1 and FEF(25-75), based on age, sex, race, weight, and height, according to Knudson standards. NO2 measurements were obtained for 4 consecutive days during 4 different periods at 20-day intervals in each kitchen. Measurements were performed inside and outside the kitchens, simultaneously using Palm diffusion tubes. A time/exposure indicator was defined as representative of the cumulative exposure of each cook. No statistically significant effect of NO2 exposure on FVC was found. Each year of work as a cook corresponded to a decrease in predicted FEV1 of 2.5% (P = 0.046) for the group as a whole. When smoking status and asthma were included in the analysis the effect of time/exposure decreased about 10% and lost statistical significance. On predicted FEF(25-75), a decrease of 3.5% (P = 0.035) was observed for the same group and the inclusion of controllers for smoking status and asthma did not affect the effects of time/exposure on pulmonary function parameter. After a 10-year period of work as cooks the participants of the study may present decreases in both predicted FEV1 and FEF(25-75) that can reach 20 and 30%, respectively. The present study showed small but statistically significant adverse effects of gas stove exposure on the lung function of professional cooks.

  16. CeO2 catalysed conversion of CO, NO2 and NO from first principles energetics

    OpenAIRE

    WATSON, GRAEME WILLIAM

    2006-01-01

    PUBLISHED First principles calculations using density functional theory with corrections for on-site Coulomb interactions (DFT + U) are presented in which we compute the energy for the conversion of CO to CO2, NO2 to NO and NO to N2 over ceria surfaces. The surface sensitivity is discussed on the basis of the vacancy formation energies We acknowledge funding from the Petroleum Research Fund administered by the American Chemical Society, Enterprise Ireland (SC/2001/233), Science Fo...

  17. Safety analysis report for packaging (SARP) of the Oak Ridge National Laboratory Garden Carrier No. 2

    International Nuclear Information System (INIS)

    Klima, B.B.; Shappert, L.B.; Seagren, R.D.; Box, W.D.

    1978-04-01

    An analytical evaluation of the Oak Ridge National Laboratory Garden Carrier No. 2 was made to demonstrate its compliance with the regulations governing off-site radioactive material shipping packages. The evaluation encompassed five primary categories: structural integrity, thermal resistance, radiation shielding, nuclear criticality safety, and quality assurance. The results of the evaluation show that the cask complies with the applicable regulations. The package is designed to ship large quantities of fissile and radioactive materials as solids

  18. Indoor NO2 air pollution and lung function of professional cooks

    Directory of Open Access Journals (Sweden)

    M.A. Arbex

    2007-04-01

    Full Text Available Studies of cooking-generated NO2 effects are rare in occupational epidemiology. In the present study, we evaluated the lung function of professional cooks exposed to NO2 in hospital kitchens. We performed spirometry in 37 cooks working in four hospital kitchens and estimated the predicted FVC, FEV1 and FEF25-75, based on age, sex, race, weight, and height, according to Knudson standards. NO2 measurements were obtained for 4 consecutive days during 4 different periods at 20-day intervals in each kitchen. Measurements were performed inside and outside the kitchens, simultaneously using Palm diffusion tubes. A time/exposure indicator was defined as representative of the cumulative exposure of each cook. No statistically significant effect of NO2 exposure on FVC was found. Each year of work as a cook corresponded to a decrease in predicted FEV1 of 2.5% (P = 0.046 for the group as a whole. When smoking status and asthma were included in the analysis the effect of time/exposure decreased about 10% and lost statistical significance. On predicted FEF25-75, a decrease of 3.5% (P = 0.035 was observed for the same group and the inclusion of controllers for smoking status and asthma did not affect the effects of time/exposure on pulmonary function parameter. After a 10-year period of work as cooks the participants of the study may present decreases in both predicted FEV1 and FEF25-75 that can reach 20 and 30%, respectively. The present study showed small but statistically significant adverse effects of gas stove exposure on the lung function of professional cooks.

  19. Five years of NO2 Mobile-DOAS measurements in Europe: an overview

    Science.gov (United States)

    Merlaud, Alexis; Fayt, Caroline; Pinardi, Gaia; Tack, Frederik; Hendrick, François; Le Roux, Anabel-Lise; Constantin, Daniel-Eduard; Voiculescu, Mirela; Shaiganfar, Reza; Wagner, Thomas; Van Roozendael, Michel

    2014-05-01

    Since the CINDI campaign held in the Netherlands in July 2009, BIRA-IASB has been operating a car-based mobile-DOAS system, primarily dedicated to tropospheric NO2 measurements. The instrument is based on two similar compact spectrometers and records scattered light spectra simultaneously in the zenith direction and 30° above the horizon, following the MAX-DOAS approach. After CINDI, Mobile-DOAS measurements were performed on a routine basis between March 2010 and August 2011, mostly across Belgium, but also in Luxembourg, France, and Germany. From 2011, another BIRA-IASB mobile-DOAS instrument, using a single zenith channel, was operated in Romania through a collaboration with the University of Galati. In June 2013, these two mobile-DOAS instruments took part in the MADCAT campaign in Mainz, Germany, together with the MPIC mobile-DOAS system, based on a mini MAX-DOAS. We describe the BIRA-IASB instruments, our strategy to retrieve the NO2 tropospheric column, and the large database that was constituted. The latter is particularly interesting for its size: it covers some 500 hours of measurements and 20 000 km, including rural, periurban and urban areas with different air quality conditions. A 2011 cloud-free subset of the measurements is compared with OMI data. We also present preliminary results of an intercomparison between the three mobile-DOAS instruments operated during MADCAT. The high spatial frequency of the measurements (around 100 m) makes them valuable to study the NO2 horizontal gradients in polluted areas. This has implications in the context of air quality satellite validation studies, in which the variability of NO2 inside a satellite pixel must be taken into account.

  20. Estimating 40 years of nitrogen deposition in global biomes using the SCIAMACHY NO2 column

    Science.gov (United States)

    Lu, Xuehe; Zhang, Xiuying; Liu, Jinxun; Jin, Jiaxin

    2016-01-01

    Owing to human activity, global nitrogen (N) cycles have been altered. In the past 100 years, global N deposition has increased. Currently, the monitoring and estimating of N deposition and the evaluation of its effects on global carbon budgets are the focus of many researchers. NO2 columns retrieved by space-borne sensors provide us with a new way of exploring global N cycles and these have the ability to estimate N deposition. However, the time range limitation of NO2 columns makes the estimation of long timescale N deposition difficult. In this study we used ground-based NOx emission data to expand the density of NO2columns, and 40 years of N deposition (1970–2009) was inverted using the multivariate linear model with expanded NO2 columns. The dynamic of N deposition was examined in both global and biome scales. The results show that the average N deposition was 0.34 g N m–2 year–1 in the 2000s, which was an increase of 38.4% compared with the 1970s’. The total N deposition in different biomes is unbalanced. N deposition is only 38.0% of the global total in forest biomes; this is made up of 25.9%, 11.3, and 0.7% in tropical, temperate, and boreal forests, respectively. As N-limited biomes, there was little increase of N deposition in boreal forests. However, N deposition has increased by a total of 59.6% in tropical forests and croplands, which are N-rich biomes. Such characteristics may influence the effects on global carbon budgets.

  1. TUNABLE DIODE LASER MEASUREMENTS OF NO2 NEAR 670 NM AND 395 NM. (R823933)

    Science.gov (United States)

    Two single-mode diode lasers were used to record high-resolution absorption spectra of NO2 (dilute in Ar) near 670.2 and 394.5 nm over a range of temperatures (296 to 774 K) and total pressures (2.4 x 10(-2) to 1 atm). A commercial InGaAsP laser was tuned 1.3 cm(-1) at a repetiti...

  2. Kinetic Behavior of Salmonella on Low NaNO2 Sausages during Aerobic and Vacuum Storage.

    Science.gov (United States)

    Ha, Jimyeong; Gwak, Eunji; Oh, Mi-Hwa; Park, Beomyoung; Lee, Jeeyeon; Kim, Sejeong; Lee, Heeyoung; Lee, Soomin; Yoon, Yohan; Choi, Kyoung-Hee

    2016-01-01

    This study evaluated the growth kinetics of Salmonella spp. in processed meat products formulated with low sodium nitrite (NaNO2). A 5-strain mixture of Salmonella spp. was inoculated on 25-g samples of sausages formulated with sodium chloride (NaCl) (1.0%, 1.25%, and 1.5%) and NaNO2 (0 and 10 ppm) followed by aerobic or vacuum storage at 10℃ and 15℃ for up to 816 h or 408 h, respectively. The bacterial cell counts were enumerated on xylose lysine deoxycholate agar, and the modified Gompertz model was fitted to the Salmonella cell counts to calculate the kinetic parameters as a function of NaCl concentration on the growth rate (GR; Log CFU/g/h) and lag phase duration (LPD; h). A linear equation was then fitted to the parameters to evaluate the effect of NaCl concentration on the kinetic parameters. The GR values of Salmonella on sausages were higher (psausages with low NaNO2.

  3. The mechanism of plasma-assisted penetration of NO2- in model tissues

    Science.gov (United States)

    He, Tongtong; Liu, Dingxin; Liu, Zhijie; Liu, Zhichao; Li, Qiaosong; Rong, Mingzhe; Kong, Michael G.

    2017-11-01

    Cold atmospheric plasmas are reportedly capable of enhancing the percutaneous absorption of drugs, which is a development direction of plasma medicine. This motivated us to study how the enhancement effect was realized. In this letter, gelatin gel films were used as surrogates of human tissues, NaNO2 was used as a representative of small-molecule drugs, and cross-field and linear-field plasma jets were used for the purpose of enhancing the penetration of NaNO2 through the gelatin gel films. The permeability of gelatin gel films was quantified by measuring the NO2- concentration in water which was covered by those films. It was found that the gas flow and electric field of cold plasmas played a crucial role in the permeability enhancement of the model tissues, but the effect of gas flow was mainly confined in the surface layer, while the effect of the electric field was holistic. Those effects might be attributed to the localized squeezing of particles by gas flow and the weakening of the ion-dipole interaction by the AC electric field. The enhancement effect decreases with the increasing mass fraction of gelatin because the macromolecules of gelatin could significantly hinder the penetration of small molecules in the model tissues.

  4. Intercomparison of ground-based ozone and NO2 measurements during the MANTRA 2004 campaign

    Directory of Open Access Journals (Sweden)

    K. Strong

    2007-11-01

    Full Text Available The MANTRA (Middle Atmosphere Nitrogen TRend Assessment 2004 campaign took place in Vanscoy, Saskatchewan, Canada (52° N, 107° W from 3 August to 15 September, 2004. In support of the main balloon launch, a suite of five zenith-sky and direct-Sun-viewing UV-visible ground-based spectrometers was deployed, primarily measuring ozone and NO2 total columns. Three Fourier transform spectrometers (FTSs that were part of the balloon payload also performed ground-based measurements of several species, including ozone. Ground-based measurements of ozone and NO2 differential slant column densities from the zenith-viewing UV-visible instruments are presented herein. They are found to partially agree within NDACC (Network for the Detection of Atmospheric Composition Change standards for instruments certified for process studies and satellite validation. Vertical column densities of ozone from the zenith-sky UV-visible instruments, the FTSs, a Brewer spectrophotometer, and ozonesondes are compared, and found to agree within the combined error estimates of the instruments (15%. NO2 vertical column densities from two of the UV-visible instruments are compared, and are also found to agree within combined error (15%.

  5. NO2 measurements in Hong Kong using LED based long path differential optical absorption spectroscopy

    Directory of Open Access Journals (Sweden)

    M. O. Wenig

    2012-05-01

    Full Text Available In this study we present the first long term measurements of atmospheric nitrogen dioxide (NO2 using a LED based Long Path Differential Optical Absorption Spectroscopy (LP-DOAS instrument. This instrument is measuring continuously in Hong Kong since December 2009, first in a setup with a 550 m absorption path and then with a 3820 m path at about 30 m to 50 m above street level. The instrument is using a high power blue light LED with peak intensity at 450 nm coupled into the telescope using a Y-fibre bundle. The LP-DOAS instrument measures NO2 levels in the Kowloon Tong and Mongkok district of Hong Kong and we compare the measurement results to mixing ratios reported by monitoring stations operated by the Hong Kong Environmental Protection Department in that area. Hourly averages of coinciding measurements are in reasonable agreement (R = 0.74. Furthermore, we used the long-term data set to validate the Ozone Monitoring Instrument (OMI NO2 data product. Monthly averaged LP-DOAS and OMI measurements correlate well (R = 0.84 when comparing the data for the OMI overpass time. We analyzed weekly patterns in both data sets and found that the LP-DOAS detects a clear weekly cycle with a reduction on weekends during rush hour peaks, whereas OMI is not able to observe this weekly cycle due to its fix overpass time (13:30–14:30 LT – local time.

  6. Simulation of Population-Based Commuter Exposure to NO2 Using Different Air Pollution Models

    Directory of Open Access Journals (Sweden)

    Martina S. Ragettli

    2014-05-01

    Full Text Available We simulated commuter routes and long-term exposure to traffic-related air pollution during commute in a representative population sample in Basel (Switzerland, and evaluated three air pollution models with different spatial resolution for estimating commute exposures to nitrogen dioxide (NO2 as a marker of long-term exposure to traffic-related air pollution. Our approach includes spatially and temporally resolved data on actual commuter routes, travel modes and three air pollution models. Annual mean NO2 commuter exposures were similar between models. However, we found more within-city and within-subject variability in annual mean (±SD NO2 commuter exposure with a high resolution dispersion model (40 ± 7 µg m−3, range: 21–61 than with a dispersion model with a lower resolution (39 ± 5 µg m−3; range: 24–51, and a land use regression model (41 ± 5 µg m−3; range: 24–54. Highest median cumulative exposures were calculated along motorized transport and bicycle routes, and the lowest for walking. For estimating commuter exposure within a city and being interested also in small-scale variability between roads, a model with a high resolution is recommended. For larger scale epidemiological health assessment studies, models with a coarser spatial resolution are likely sufficient, especially when study areas include suburban and rural areas.

  7. Ce doped NiO nanoparticles as selective NO2 gas sensor

    Science.gov (United States)

    Gawali, Swati R.; Patil, Vithoba L.; Deonikar, Virendrakumar G.; Patil, Santosh S.; Patil, Deepak R.; Patil, Pramod S.; Pant, Jayashree

    2018-03-01

    Metal oxide gas sensors are promising portable gas detection devices because of their advantages such as low cost, easy production and compact size. The performance of such sensors is strongly dependent on material properties such as morphology, structure and doping. In the present study, we report the effect of cerium (Ce) doping on nickel oxide (NiO) nano-structured thin film sensors towards various gases. Bare NiO and Ce doped NiO nanoparticles (Ce:NiO) were synthesized by sol-gel method. To understand the effect of Ce doping in nickel oxide, various molar percentages of Ce with respect to nickel were incorporated. The structure, phase, morphology and band-gap energy of as-synthesized nanoparticles were studied by XRD, SEM, EDAX and UV-vis spectroscopy. Thin film gas sensors of all the samples were prepared and subjected to various gases such as LPG, NH3, CH3COCH3 and NO2. A systematic and comparative study reveals an enhanced gas sensing performance of Ce:NiO sensors towards NO2 gas. The maximum sensitivity for NO2 gas is around 0.719% per ppm at moderate operating temperature of 150 °C for 0.5% Ce:NiO thin film gas sensor. The enhanced gas sensing performance for Ce:NiO is attributed to the distortion of crystal lattice caused by doping of Ce into NiO.

  8. Kinetics of the Reactions of IO Radicals with NO and NO2

    Science.gov (United States)

    Daykin, E. P.; Wine, P. H.

    1997-01-01

    A laser flash photolysis-long path absorption technique has been employed to study the kinetics of the reactions of IO radicals with NO and NO2 as a function of temperature and pressure. The IO and NO rate coefficient is independent of pressure over the range 40-200 Torr of N2, and its temperature dependence over the range 242-359 K is adequately described by the Arrhenius expression k(sub 1) = (6.9 +/- 1.7) x 10(exp -12) exp[(328 +/- 71)/T] cu cm/(molecule.s) (errors are 2 sigma, precision only). These Arrhenius parameters are similar to those determined previously for the ClO + NO and BrO + NO reactions. The IO and NO2 association reaction is found to be in the falloff regime over the temperature and pressure ranges investigated (254-354 K and 40-750 Torr of N2). Assuming F(sub c) = 0.4 independent of temperature, a physically reasonable set of falloff parameters which adequately describe the data are k(sub 0) = 7.7 x 10(exp -31)(T/300)(exp -5.0) cm(exp 6)/(molecule(exp 2).s) and k(sub infinity) = 1.55 x 10(exp -11)cu cm/(molecule.s) independent of temperature. The IO + NO2 rate coefficients determined in this study are about a factor of 2 faster than those reported in the only previous study of this reaction.

  9. Heterogeneous Reactions between Toluene and NO2 on Mineral Particles under Simulated Atmospheric Conditions.

    Science.gov (United States)

    Niu, Hejingying; Li, Kezhi; Chu, Biwu; Su, Wenkang; Li, Junhua

    2017-09-05

    Heterogeneous reactions between organic and inorganic gases with aerosols are important for the study of smog occurrence and development. In this study, heterogeneous reactions between toluene and NO 2 with three atmospheric mineral particles in the presence or absence of UV light were investigated. The three mineral particles were SiO 2 , α-Fe 2 O 3 , and BS (butlerite and szmolnokite). In a dark environment, benzaldehyde was produced on α-Fe 2 O 3 . For BS, nitrotoluene and benzaldehyde were obtained. No aromatic products were produced in the absence of NO 2 in the system. In the presence of UV irradiation, benzaldehyde was detected on the SiO 2 surface. Identical products were produced in the presence and absence of UV light over α-Fe 2 O 3 and BS. UV light promoted nitrite to nitrate on mineral particles surface. On the basisi of the X-ray photoelectron spectroscopy (XPS) results, a portion of BS was reduced from Fe 3+ to Fe 2+ with the adsorption of toluene or the reaction with toluene and NO 2 . Sulfate may play a key role in the generation of nitrotoluene on BS particles. From this research, the heterogeneous reactions between organic and inorganic gases with aerosols that occur during smog events will be better understood.

  10. What You Need to Know About the OMI NO2 Data Product for Air Quality Studies

    Science.gov (United States)

    Celarier, E. A.; Gleason, J. F.; Bucsela, E. J.; Brinksma, E.; Veefkind, J. P.

    2007-01-01

    The standard nitrogen dioxide (NO2) data product, produced from measurements by the Ozone Monitoring Instrument (OMI), are publicly available online from the NASA GESDISC facility. Important data fields include total and tropospheric column densities, as well as collocated data for cloud fraction and cloud top height, surface albedo and snow/ice coverage, at the resolution of the OMI instrument (12 km x 26 km, at nadir). The retrieved NO2 data have been validated, principally under clear-sky conditions. The first public-release version has been available since September 2006. An improved version of the data product, which includes a number of new data fields, and improved estimates of the retrieval uncertainties will be released by the end of 2007. This talk will describe the standard NO2 data product, including details that are essential for the use of the data for air quality studies. We will also describe the principal improvements with the new version of the data product.

  11. Trace elements and human fertility.

    OpenAIRE

    Stovell, Alex Gordon.

    1999-01-01

    Methods were developed and validated for the analysis of trace elements in human scalp hair, blood serum, ovarian follicular fluid and seminal plasma by inductively coupled plasma mass spectrometry (ICP-MS). An interlaboratory comparison was also undertaken to compare the analysis of biological materials by ICP-MS with instrumental neutron activation analysis (INAA). Preliminary trace element protein speciation experiments were carried out using size exclusion high performance liquid chromato...

  12. Inversion of tropospheric profiles of aerosol extinction and HCHO and NO2 mixing ratios from MAX-DOAS observations in Milano during the summer of 2003 and comparison with independent data sets

    Directory of Open Access Journals (Sweden)

    U. Platt

    2011-12-01

    Full Text Available We present aerosol and trace gas profiles derived from MAX-DOAS observations. Our inversion scheme is based on simple profile parameterisations used as input for an atmospheric radiative transfer model (forward model. From a least squares fit of the forward model to the MAX-DOAS measurements, two profile parameters are retrieved including integrated quantities (aerosol optical depth or trace gas vertical column density, and parameters describing the height and shape of the respective profiles. From these results, the aerosol extinction and trace gas mixing ratios can also be calculated. We apply the profile inversion to MAX-DOAS observations during a measurement campaign in Milano, Italy, September 2003, which allowed simultaneous observations from three telescopes (directed to north, west, south. Profile inversions for aerosols and trace gases were possible on 23 days. Especially in the middle of the campaign (17–20 September 2003, enhanced values of aerosol optical depth and NO2 and HCHO mixing ratios were found. The retrieved layer heights were typically similar for HCHO and aerosols. For NO2, lower layer heights were found, which increased during the day. The MAX-DOAS inversion results are compared to independent measurements: (1 aerosol optical depth measured at an AERONET station at Ispra; (2 near-surface NO2 and HCHO (formaldehyde mixing ratios measured by long path DOAS and Hantzsch instruments at Bresso; (3 vertical profiles of HCHO and aerosols measured by an ultra light aircraft. Depending on the viewing direction, the aerosol optical depths from MAX-DOAS are either smaller or larger than those from AERONET observations. Similar comparison results are found for the MAX-DOAS NO2 mixing ratios versus long path DOAS measurements. In contrast, the MAX-DOAS HCHO mixing ratios are generally higher than those from long path DOAS or Hantzsch instruments. The comparison of the HCHO and aerosol profiles from the aircraft showed reasonable

  13. Traces Synchronization in Distributed Networks

    Directory of Open Access Journals (Sweden)

    Eric Clément

    2009-01-01

    Full Text Available This article proposes a novel approach to synchronize a posteriori the detailed execution traces from several networked computers. It can be used to debug and investigate complex performance problems in systems where several computers exchange information. When the distributed system is under study, detailed execution traces are generated locally on each system using an efficient and accurate system level tracer, LTTng. When the tracing is finished, the individual traces are collected and analysed together. The messaging events in all the traces are then identified and correlated in order to estimate the time offset over time between each node. The time offset computation imprecision, associated with asymmetric network delays and operating system latency in message sending and receiving, is amortized over a large time interval through a linear least square fit over several messages covering a large time span. The resulting accuracy is such that it is possible to estimate the clock offsets in a distributed system, even with a relatively low volume of messages exchanged, to within the order of a microsecond while having a very low impact on the system execution, which is sufficient to properly order the events traced on the individual computers in the distributed system.

  14. FormTracer. A mathematica tracing package using FORM

    Science.gov (United States)

    Cyrol, Anton K.; Mitter, Mario; Strodthoff, Nils

    2017-10-01

    We present FormTracer, a high-performance, general purpose, easy-to-use Mathematica tracing package which uses FORM. It supports arbitrary space and spinor dimensions as well as an arbitrary number of simple compact Lie groups. While keeping the usability of the Mathematica interface, it relies on the efficiency of FORM. An additional performance gain is achieved by a decomposition algorithm that avoids redundant traces in the product tensors spaces. FormTracer supports a wide range of syntaxes which endows it with a high flexibility. Mathematica notebooks that automatically install the package and guide the user through performing standard traces in space-time, spinor and gauge-group spaces are provided. Program Files doi:http://dx.doi.org/10.17632/7rd29h4p3m.1 Licensing provisions: GPLv3 Programming language: Mathematica and FORM Nature of problem: Efficiently compute traces of large expressions Solution method: The expression to be traced is decomposed into its subspaces by a recursive Mathematica expansion algorithm. The result is subsequently translated to a FORM script that takes the traces. After FORM is executed, the final result is either imported into Mathematica or exported as optimized C/C++/Fortran code. Unusual features: The outstanding features of FormTracer are the simple interface, the capability to efficiently handle an arbitrary number of Lie groups in addition to Dirac and Lorentz tensors, and a customizable input-syntax.

  15. TEA CO2 laser-induced reaction of CH3NO2 with CF2HCl: A ...

    Indian Academy of Sciences (India)

    Unknown

    CH3NO2. Time-resolved infrared fluorescence from vibrationally excited CF2HCl and CH3NO2 molecules as well as ... nitromethane, dissociation into CH3 and NO2 radicals is the most efficient [φ = 0⋅6]. *For correspondence ... Quantitative analysis could not be done because of the complexity of the reaction products and ...

  16. 40 CFR 53.32 - Test procedures for methods for SO2, CO, O3, and NO2.

    Science.gov (United States)

    2010-07-01

    ..., O3, and NO2. 53.32 Section 53.32 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... for SO2, CO, O3, and NO2. (a) Comparability. Comparability is shown for SO2, CO, O3, and NO2 methods... twenty-four (24) sequential 1-hour measurements. (6) For O3 and CO, no more than six 1-hour measurements...

  17. 75 FR 29334 - Public Utility District No. 2 of Grant County, WA; Notice of Application for Amendment of License...

    Science.gov (United States)

    2010-05-25

    ... Energy Regulatory Commission Public Utility District No. 2 of Grant County, WA; Notice of Application for...: February 26, 2010. d. Applicant: Public Utility District No. 2 of Grant County, Washington. e. Name of.... Applicant Contact: Kelly Larimer, Lands and Recreation Resources Manager, Public Utility District No. 2 of...

  18. 75 FR 30807 - Public Utility District No. 2 of Grant County, WA; Notice of Application for Amendment of License...

    Science.gov (United States)

    2010-06-02

    ... Energy Regulatory Commission Public Utility District No. 2 of Grant County, WA; Notice of Application for... Filed: March 2, 2010, supplemented April 20, 2010. d. Applicant: Public Utility District No. 2 of Grant..., Lands and Recreation Resources Manager, Public Utility District No. 2 of Grant County, P.O. Box 878...

  19. Trace Elements in Teeth by ICPMS

    International Nuclear Information System (INIS)

    Zahran, N.F.; Helal, A.I.; Amr, M.A.; Amr, M.A.; Al-saad, K.A.

    2008-01-01

    Teeth are reported to be suitable indicators of trace element exposure from environment and nutritional status. Inductively coupled plasma mass spectrometry (ICP-MS) is used to compare the trace element content of children's primary teeth and adult teeth. Primary teeth are collected from 28 children and 42 adult from non-industrial City. The data are assessed statistically using t-tests. The adult teeth contained significantly greater concentrations of Na, Mg, Al, Fe, Ni, Cu, Sr, Cd, Ba, Pb and U and significantly less Mn, Co, As, Se, Mo and Bi than the children teeth. Additional measurements on adult teeth pulps are performed. Comparison between trace element concentrations in health and caries teeth pulps show that the mean concentrations of Na, Al, K, Cr, Mn, Co, Cu, Zn, Mo, Ag, Bi and U are lower in caries than healthy teeth pulps. On the other hand, the mean concentrations of Mg, Cd and Pb are higher in caries samples than healthy teeth pulps

  20. An inventory survey at the site of the proposed Kilauea Middle East Rift Zone (KMERZ), Well Site No. 2

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Joseph

    1991-03-01

    At the request of True Mid Pacific Geothermal, Archaeological Consultants of Hawaii, Inc. has conducted an inventory survey at the site of the proposed Kilauea Middle East Rift Zone (KMERZ), Well Site No.2, TMK: 1-2-10:3. The Principal Investigator was Joseph Kennedy M.A., assisted by Jacob Kaio, Field Supervisor and field crew Mark Borrello B.A., Michael O'Shaughnessy B.A., and Randy Adric. This report supercedes all previous reports submitted to the Historic Presentation Section of the Department of Land and Natural Resources. In addition to 100% surface coverage of the 400 x 400 foot well pad itself, 100% surface coverage of a substantial buffer zone was also completed. This buffer zone was established by the Department of Land and Natural Resources, Historic Preservation personnel and extends 1000 feet east and west of the well site and 500 feet north and south of the well site.

  1. Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2015

    Science.gov (United States)

    Krotkov, Nickolay A.; McLinden, Chris A; Li, Can; Lamsal, Lok N.; Celarier, Edward A.; Marchenko, Sergey V.; Swartz, William H.; Bucsela, Eric J.; Joiner, Joanna; Duncan, Bryan N.; hide

    2016-01-01

    The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2/ and sulfur dioxide (SO2/, since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper, we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2015, by more than 40 and 80 %, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal-fired power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50% reduction in 2012- 2015, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 %, respectively, from 2005 to 2015. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved valuable in documenting rapid changes in air quality over different

  2. Field calibration of electrochemical NO2 sensors in a citizen science context

    Science.gov (United States)

    Mijling, Bas; Jiang, Qijun; de Jonge, Dave; Bocconi, Stefano

    2018-03-01

    In many urban areas the population is exposed to elevated levels of air pollution. However, real-time air quality is usually only measured at few locations. These measurements provide a general picture of the state of the air, but they are unable to monitor local differences. New low-cost sensor technology is available for several years now, and has the potential to extend official monitoring networks significantly even though the current generation of sensors suffer from various technical issues.Citizen science experiments based on these sensors must be designed carefully to avoid generation of data which is of poor or even useless quality. This study explores the added value of the 2016 Urban AirQ campaign, which focused on measuring nitrogen dioxide (NO2) in Amsterdam, the Netherlands. Sixteen low-cost air quality sensor devices were built and distributed among volunteers living close to roads with high traffic volume for a 2-month measurement period. Each electrochemical sensor was calibrated in-field next to an air monitoring station during an 8-day period, resulting in R2 ranging from 0.3 to 0.7. When temperature and relative humidity are included in a multilinear regression approach, the NO2 accuracy is improved significantly, with R2 ranging from 0.6 to 0.9. Recalibration after the campaign is crucial, as all sensors show a significant signal drift in the 2-month measurement period. The measurement series between the calibration periods can be corrected for after the measurement period by taking a weighted average of the calibration coefficients.Validation against an independent air monitoring station shows good agreement. Using our approach, the standard deviation of a typical sensor device for NO2 measurements was found to be 7 µg m-3, provided that temperatures are below 30 °C. Stronger ozone titration on street sides causes an underestimation of NO2 concentrations, which 75 % of the time is less than 2.3 µg m-3.Our findings show that citizen science

  3. Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2015

    Directory of Open Access Journals (Sweden)

    N. A. Krotkov

    2016-04-01

    Full Text Available The Ozone Monitoring Instrument (OMI onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2 and sulfur dioxide (SO2, since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper, we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2015, by more than 40 and 80 %, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal-fired power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50 % reduction in 2012–2015, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 %, respectively, from 2005 to 2015. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved valuable in documenting rapid changes in air

  4. Two Catacombs of Late Sarmatian Time From Pashkovsky Burial Mound no. 2

    Directory of Open Access Journals (Sweden)

    Limberis Natalya Yuryevna

    2015-12-01

    Full Text Available The article deals with two burials from the Kuban basin region excavated in Pashkovsky burial mound no. 2 belonging to Maeotian Pashkovskoe ancient settlement. The burials were made in catacombs of similar construction and orientation. The narrow grave entrances and grave chambers are situated in-line. The grave chambers of the catacombs adjoin one other that probably was the reason for plunder of a little earlier burial no. 2. There were the complete horse skeleton, the cow skull and the sheep chap in the grave entrance ofthe catacomb no. 2. A skeleton of a man (about 50 years old was in extended supine position diagonally across the grave chamber, his scull had SSW orientation. Grave goods found near the buried man include the gray-clay bowl and the mug-jar, the iron spearhead, the long sword and the dagger, the bit with wheel-shaped cheek-pieces, the sickle, the knives and the shoe buckles, the glass bead, the chalk rock bead, the bronze buckle and fibula. The catacomb no. 2 plundered in ancient times situated north-ward of the first one, the southern border of the grave chamber is partially cutted by catacomb no. 1. In the grave entrance of the catacomb no. 1 there were the remains of the horse skeleton and the sheep skull. Grave goods scattered in grave chamber included the gray-clay bowl, pieces of chalk, the bronze ring, fragments of the iron buckle, rod, hasp, silver temple ring, bronze escutcheon for the box lock, the iron snap-up loop and fragments of silver flacon with a cover. Late Sarmatian burial rites and grave goods give evidence of the belonging these burials to spokesmen of the equestrian order. The chronological range of the burials stays within terms from the second half of 2nd to the middle of 3rd century A.D. The lower date of the catacomb no. 1 turns toward the end of the 2nd century A.D., the upper date is limited by the first half of the 3rd century A.D. The catacomb no. 2 is stratigraphically older. The eques status of

  5. Cytocompatible cellulose hydrogels containing trace lignin

    Energy Technology Data Exchange (ETDEWEB)

    Nakasone, Kazuki; Kobayashi, Takaomi, E-mail: takaomi@nagaoakut.ac.jp

    2016-07-01

    Sugarcane bagasse was used as a cellulose resource to prepare transparent and flexible cellulose hydrogel films. On the purification process from bagasse to cellulose, the effect of lignin residues in the cellulose was examined for the properties and cytocompatibility of the resultant hydrogel films. The cellulose was dissolved in lithium chloride/N,N-dimethylacetamide solution and converted to hydrogel films by phase inversion. In the purification process, sodium hydroxide (NaOH) treatment time was changed from 1 to 12 h. This resulted in cellulose hydrogel films having small amounts of lignin from 1.62 to 0.68%. The remaining lignin greatly affected hydrogel properties. Water content of the hydrogel films was increased from 1153 to 1525% with a decrease of lignin content. Moreover, lower lignin content caused weakening of tensile strength from 0.80 to 0.43 N/mm{sup 2} and elongation from 45.2 to 26.5%. Also, similar tendency was observed in viscoelastic behavior of the cellulose hydrogel films. Evidence was shown that the lignin residue was effective for the high strength of the hydrogel films. In addition, scanning probe microscopy in the morphological observation was suggested that the trace lignin in the cellulose hydrogel affected the cellulose fiber aggregation in the hydrogel network. The trace of lignin in the hydrogels also influenced fibroblast cell culture on the hydrogel films. The hydrogel film containing 1.68% lignin showed better fibroblast compatibility as compared to cell culture polystyrene dish used as reference. - Highlights: • Cellulose hydrogel films with trace lignin were obtained from sugarcane bagasse. • Lignin content was found to be in the range of 1.62 − 0.68% by UV–Vis spectroscopy. • Higher lignin content strengthened mechanical properties of the hydrogel films. • Trace lignin affected the hydrogel morphology such as roughness and porosity. • High cell proliferation was observed in the hydrogel containing 1.68% lignin.

  6. Formation of indoor nitrous acid (HONO) by light-induced NO2 heterogeneous reactions with white wall paint.

    Science.gov (United States)

    Bartolomei, Vincent; Sörgel, Matthias; Gligorovski, Sasho; Alvarez, Elena Gómez; Gandolfo, Adrien; Strekowski, Rafal; Quivet, Etienne; Held, Andreas; Zetzsch, Cornelius; Wortham, Henri

    2014-01-01

    Gaseous nitrogen dioxide (NO2) represents an oxidant that is present in relatively high concentrations in various indoor settings. Remarkably increased NO2 levels up to 1.5 ppm are associated with homes using gas stoves. The heterogeneous reactions of NO2 with adsorbed water on surfaces lead to the generation of nitrous acid (HONO). Here, we present a HONO source induced by heterogeneous reactions of NO2 with selected indoor paint surfaces in the presence of light (300 nmpaint surfaces to generate HONO within indoor environments by light-induced NO2 heterogeneous reactions.

  7. Relationship of atmospheric pollution characterized by gas (NO2) and particles (PM10) to microbial communities living in bryophytes at three differently polluted sites (rural, urban, and industrial).

    Science.gov (United States)

    Meyer, Caroline; Gilbert, Daniel; Gaudry, André; Franchi, Marielle; Nguyen, Hung Viet; Fabure, Juliette; Bernard, Nadine

    2010-02-01

    Atmospheric pollution has become a major problem for modern societies owing to its fatal effects on both human health and ecosystems. We studied the relationships of nitrogen dioxide atmospheric pollution and metal trace elements contained in atmospheric particles which were accumulated in bryophytes to microbial communities of bryophytes at three differently polluted sites in France (rural, urban, and industrial) over an 8-month period. The analysis of bryophytes showed an accumulation of Cr and Fe at the rural site; Cr, Fe, Zn, Cu, Al, and Pb at the urban site; and Fe, Cr, Pb, Al, Sr, Cu, and Zn at the industrial site. During this study, the structure of the microbial communities which is characterized by biomasses of microbial groups evolved differently according to the site. Microalgae, bacteria, rotifers, and testate amoebae biomasses were significantly higher in the rural site. Cyanobacteria biomass was significantly higher at the industrial site. Fungal and ciliate biomasses were significantly higher at the urban and industrial sites for the winter period and higher at the rural site for the spring period. The redundancy analysis showed that the physico-chemical variables ([NO(2)], relative humidity, temperature, and site) and the trace elements which were accumulated in bryophytes ([Cu], [Sr], [Pb]) explained 69.3% of the variance in the microbial community data. Moreover, our results suggest that microbial communities are potential biomonitors of atmospheric pollution. Further research is needed to understand the causal relationship underlined by the observed patterns.

  8. Isotope tracing enhancement of chemiluminescence assays for nitric oxide research.

    Science.gov (United States)

    Cornelius, Julia; Tran, Tuan; Turner, Nicole; Piazza, Abigail; Mills, Lauren; Slack, Ryan; Hauser, Sean; Alexander, J Steven; Grisham, Matthew B; Feelisch, Martin; Rodriguez, Juan

    2009-02-01

    Chemiluminescence assays are used widely for the detection of nitric oxide (NO)-derived species in biological fluids and tissues. Here, we demonstrate that these assays can be interfaced with mass-sensitive detectors for parallel determination of isotopic abundance. Results obtained with tri-iodide and ascorbic acid-based reductive assays indicate that mass spectrometric detection enables NO isotope-tracing experiments to be carried out to a limit of detectability of a few picomoles, a sensitivity similar to that of standard gas phase chemiluminescence methods. The advantage afforded by mass spectrometric detection is demonstrated using the murine macrophage cell line J774, which is shown here to reduce 15NO3- to 15NO2- under anoxic conditions. The particular combination of an analytical and cellular system described here may hold promise for future characterization of the enzymatic pathways contributing to mammalian nitrate reductase activity, without background interference from 14NO2- derived from other sources.

  9. Effect of surface BRDF of various land cover types on geostationary observations of tropospheric NO2

    Science.gov (United States)

    Noguchi, K.; Richter, A.; Rozanov, V.; Rozanov, A.; Burrows, J. P.; Irie, H.; Kita, K.

    2014-10-01

    We investigated the effect of surface reflectance anisotropy, bidirectional reflectance distribution function (BRDF), on satellite retrievals of tropospheric NO2. We assume the geometry of geostationary measurements over Tokyo, which is one of the worst air-polluted regions in East Asia. We calculated air mass factors (AMF) and box AMFs (BAMF) for tropospheric NO2 to evaluate the effect of BRDF by using the radiative transfer model SCIATRAN. To model the BRDF effect, we utilized the Moderate Resolution Imaging Spectroradiometer (MODIS) products (MOD43B1 and MOD43B2), which provide three coefficients to express the RossThick-LiSparse reciprocal model, a semi-empirical and kernel-based model of BRDF. Because BRDF depends on the land cover type, we also utilized the High Resolution Land-Use and Land-Cover Map of the Advanced Land Observing Satellite (ALOS)/Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2), which classifies the ground pixels over Tokyo into six main types: water, urban, paddy, crop, deciduous forest, and evergreen forest. We first develop an empirical model of the three BRDF coefficients for each land cover type over Tokyo and then apply the model to the calculation of land-cover-type-dependent AMFs and BAMFs. Results show that the variability of AMF among the land types is up to several tens of percent, and if we neglect the reflectance anisotropy, the difference with AMFs based on BRDF reaches 10% or more. The evaluation of the BAMFs calculated shows that not considering BRDF will cause large errors if the concentration of NO2 is high close to the surface, although the importance of BRDF for AMFs decreases for large aerosol optical depth (AOD).

  10. Health risks of NO 2, SPM and SO 2 in Delhi (India)

    Science.gov (United States)

    Pandey, Jai Shanker; Kumar, Rakesh; Devotta, Sukumar

    There is increasingly growing evidence linking urban air pollution to acute and chronic illnesses amongst all age groups. Therefore, monitoring of ambient concentrations of various air pollutants as well as quantification of the dose inhaled becomes quite important, specially in view of the fact that in many countries, policy decisions for reducing pollutant concentrations are mainly taken on the basis of their health impacts. The dose when gets combined with the likely responses, indicates the ultimate health risk (HR). Thus, as an extension of our earlier studies, HR has been estimated for three pollutants, namely, suspended particulate matter (SPM), nitrogen dioxide (NO 2) and sulfur dioxide (SO 2) for Delhi City in India. For estimation and analyses, three zones have been considered, namely, residential, industrial and commercial. The total population has been divided into three age classes (infants, children and adults) with different body weights and breathing rates. The exercise takes into account age-specific breathing rates, body weights for different age categories and occupancy factors for different zones. Results indicate that health risks due to air pollution in Delhi are highest for children. For all age categories, health risks due to SO 2 (HR_SO 2) are the lowest. Hence, HR_SO 2 has been taken as the reference with respect to which HR values due to SPM and NO 2 have been compared. Taking into account all the age categories and their occupancy in different zones, average HR values for NO 2 and SPM turn out to be respectively 22.11 and 16.13 times more than that for SO 2. The present study can be useful in generating public awareness as well as in averting and mitigating the health risks.

  11. Product analysis during the thermo-oxidation of amorphous deuterated hydrocarbon films with NO2

    Directory of Open Access Journals (Sweden)

    D. Alegre

    2015-12-01

    Full Text Available The excellent thermo-oxidation properties of NO2 have been previously reported, pointing to fast carbon co-deposits removal even at temperatures as low as 200 °C. On the other hand, CO, CO2 and water have been found as the main gas products in oxidation by O2, but in NO2 they have not been confirmed. To make a more accurate assessment, the use of in-situ deposited deuterated hydrocarbon films—to be able to distinguish products from ambient, protonated ones—in a fully-baked chamber have been used in the present work, mainly aimed at detecting heavy (deuterated water among the reaction products. Other products from hydrogen isotopes could not be identified, but their production would be much lower than water. The ratio of the total deuterium to carbon products detected is lower by an order of magnitude than the D/C ratio of the film (0.04–0.07 to 0.4, probably associated to the difficulties of measuring water in a vacuum system, and the relatively large quantity of background water found. Furthermore, post-oxidation of CO to CO2 has been found for NO2 at any studied temperature, while for O2 a faster post-oxidation which only occurs at T > 275 °C was found. Finally, the implications of the water production in the use of thermo-oxidation in actual and future nuclear fusion devices are also addressed.

  12. 5 year Survey of Carcinoma Breast at No.(2) Military Hospital (1987 to 1991)

    International Nuclear Information System (INIS)

    Aye Pe; Kaythi Saw; Shu Mon; Yin Yin Aung

    1993-03-01

    Over 250 cases of carcinoma of Breast in different stages, treated by Joint Cancer Clinic (JCC) of No (2) Military Hospital over 5 years (1987 to 1991) were analysed. Different combination of drugs CMF, CMF(P),CMFVP and COFA regimes were given either alone on in combination with local radiation therapy after surgery- lumpectomy or extended simple mastectomy. Hormonal therapy was also added to the standard method of treatment in most of the cases. Results were evaluated in different arms of treatment. The value of immunotherapy and neochemotherapy were also studied

  13. Middle distillate price monitoring system. Interim validation report. [No. 2 heating oil

    Energy Technology Data Exchange (ETDEWEB)

    Hopelain, D.G.; Freedman, D.; Rice, T.H.; Veitch, J.G.; Finlay, A.

    1978-12-01

    The Middle Distillate Price Monitoring System collects data on prices and gross margins for No. 2 heating oil from a sample of refiners, resellers, and retailers. The data is used to evaluate the level of competition and the reasonableness of prices in the heating oil market. It is concluded that the data does not provide a basis for determining whether a market is competitive, and that there is serious doubt as to the accuracy of the information collected by the system. Some recommendations are given for improving the quality of the information. (DLC)

  14. Reduced Graphene Oxide/Au Nanocomposite for NO2 Sensing at Low Operating Temperature

    Directory of Open Access Journals (Sweden)

    Hao Zhang

    2016-07-01

    Full Text Available A reduced grapheme oxide (rGO/Au hybrid nanocomposite has been synthesized by hydrothermal treatment using graphite and HAuCl4 as the precursors. Characterization, including X-ray diffraction (XRD, Raman spectra, X-ray photoelecton spectroscopy (XPS and transmission electron microscopy (TEM, indicates the formation of rGO/Au. A gas sensor fabricated with rGO/Au nanocomposite was applied for NO2 detection at 50 °C. Compared with pure rGO, rGO/Au nanocomposite exhibits higher sensitivity, a more rapid response–recovery process and excellent reproducibility.

  15. A Theory of Network Tracing

    Science.gov (United States)

    Acharya, Hrishikesh B.; Gouda, Mohamed G.

    Traceroute is a widely used program for computing the topology of any network in the Internet. Using Traceroute, one starts from a node and chooses any other node in the network. Traceroute obtains the sequence of nodes that occur between these two nodes, as specified by the routing tables in these nodes. Each use of Traceroute in a network produces a trace of nodes that constitute a simple path in this network. In every trace that is produced by Traceroute, each node occurs either by its unique identifier, or by the anonymous identifier"*". In this paper, we introduce the first theory aimed at answering the following important question. Is there an algorithm to compute the topology of a network N from a trace set T that is produced by using Traceroute in network N, assuming that each edge in N occurs in at least one trace in T, and that each node in N occurs by its unique identifier in at least one trace in T? We prove that the answer to this question is "No" if N is an even ring or a general network. However, it is "Yes" if N is a tree or an odd ring. The answer is also "No" if N is mostly-regular, but "Yes" if N is a mostly-regular even ring.

  16. Variability of O3 and NO2 profile shapes during DISCOVER-AQ: Implications for satellite observations and comparisons to model-simulated profiles

    Science.gov (United States)

    Flynn, Clare Marie; Pickering, Kenneth E.; Crawford, James H.; Weinheimer, Andrew J.; Diskin, Glenn; Thornhill, K. Lee; Loughner, Christopher; Lee, Pius; Strode, Sarah A.

    2016-12-01

    To investigate the variability of in situ profile shapes under a variety of meteorological and pollution conditions, results are presented of an agglomerative hierarchical cluster analysis of the in situ O3 and NO2 profiles for each of the four campaigns of the NASA DISCOVER-AQ mission. Understanding the observed profile variability for these trace gases is useful for understanding the accuracy of the assumed profile shapes used in satellite retrieval algorithms as well as for understanding the correlation between satellite column observations and surface concentrations. The four campaigns of the DISCOVER-AQ mission took place in Maryland during July 2011, the San Joaquin Valley of California during January-February 2013, the Houston, Texas, metropolitan region during September 2013, and the Denver-Front Range region of Colorado during July-August 2014. Several distinct profile clusters emerged for the California, Texas, and Colorado campaigns for O3, indicating significant variability of O3 profile shapes, while the Maryland campaign presented only one distinct O3 cluster. In contrast, very few distinct profile clusters emerged for NO2 during any campaign for this particular clustering technique, indicating the NO2 profile behavior was relatively uniform throughout each campaign. However, changes in NO2 profile shape were evident as the boundary layer evolved through the day, but they were apparently not significant enough to yield more clusters. The degree of vertical mixing (as indicated by temperature lapse rate) associated with each cluster exerted an important influence on the shapes of the median cluster profiles for O3, as well as impacted the correlations between the associated column and surface data for each cluster for O3. The correlation analyses suggest satellites may have the best chance to relate to surface O3 under the conditions encountered during the Maryland campaign Clusters 1 and 2, which include deep, convective boundary layers and few

  17. Comparison of Satellite NO2 Observations with High Resolution Model Simulations over the Balkan Peninsula

    International Nuclear Information System (INIS)

    Zyrichidou, I.; Koukouli, M. E.; Balis, D. S.; Katragkou, E.; Poupkou, A.; Kioutsioukis, I.; Markakis, K.; Melas, D.; van der A., R.; Boersma, F. K.; Roozendael, M. van

    2010-01-01

    High resolution model estimations of tropospheric NO 2 column amounts from the Comprehensive Air Quality Model (CAMx) were simulated for the Balkan Peninsula and were compared with satellite data for a period of one year, in order to study the characteristics of the spatial and temporal variability of pollution in the area. The Balkan area is considered a crossroad of different pollution sources and therefore has been divided in urban, industrial and rural regions, aiming to investigate the consistency of satellite retrievals and model predictions at high spatial resolution. Satellite measurements of tropospheric NO 2 are available daily at 13:30 LT since 2004 from OMI/Aura with a resolution of 13x24 km. The anthropogenic emissions used in CAMx for the domain under study, was compiled employing bottom-up approaches (road transport sector, off-road machinery) as well as other national registries and international databases. High resolution GIS maps (road network, landuses, population) were also used in order to achieve high spatial resolution. In most of the cases the model reveals similar spatial patterns with the satellite data, while over certain areas discrepancies were found and investigated.

  18. Acidic gases (CO2, NO2 and SO2) capture and dissociation on metal decorated phosphorene

    Science.gov (United States)

    Kuang, Anlong; Kuang, Minquan; Yuan, Hongkuan; Wang, Guangzhao; Chen, Hong; Yang, Xiaolan

    2017-07-01

    Density functional theory is employed to investigate the adsorption and dissociation of several acidic gases (CO2, NO2 and SO2) on metal (Li, Al, Ni and Pt) decorated phosphorene. The results show that light metal (Li, Al) decorated phosphorene exhibits a strong adsorption of acidic gases, i.e., the adsorption energy of CO2 on Li decorated phosphorene is 0.376 eV which is the largest in all adsorption of CO2 on metal decorated phosphorene and Al decorated phosphorene is most effective for capture of NO2 and SO2 due to large adsorption energies of 3.951 and 3.608 eV, respectively. Moreover, Li and Al light metals have stronger economic effectiveness and more friendly environment compared with the transition metals, the strong adsorption ability of acidic gases and low price suggest that Li, Al decorated phosphorene may be useful and promising for collection and filtration of exhaust gases. The reaction energy barriers of acidic gases dissociated process on Pt decorated phosphorene are relatively low and the reaction processes are significantly exothermic, indicating that the dissociation process is favorable.

  19. Typical meteorological conditions associated with extreme nitrogen dioxide (NO2 pollution events over Scandinavia

    Directory of Open Access Journals (Sweden)

    M. A. Thomas

    2017-10-01

    Full Text Available Characterizing typical meteorological conditions associated with extreme pollution events helps to better understand the role of local meteorology in governing the transport and distribution of pollutants in the atmosphere. The knowledge of their co-variability could further help to evaluate and constrain chemistry transport models. Hence, in this study, we investigate the statistical linkages between extreme nitrogen dioxide (NO2 pollution events and meteorology over Scandinavia using observational and reanalysis data. It is observed that the south-westerly winds dominated during extreme events, accounting for 50–65 % of the total events depending on the season, while the second largest annual occurrence was from south-easterly winds, accounting for 17 % of total events. The specific humidity anomalies showed an influx of warmer and moisture-laden air masses over Scandinavia in the free troposphere. Two distinct modes in the persistency of circulation patterns are observed. The first mode lasts for 1–2 days, dominated by south-easterly winds that prevailed during 78 % of total extreme events in that mode, while the second mode lasted for 3–5 days, dominated by south-westerly winds that prevailed during 86 % of the events. The combined analysis of circulation patterns, their persistency, and associated changes in humidity and clouds suggests that NO2 extreme events over Scandinavia occur mainly due to long-range transport from the southern latitudes.

  20. Al-Sn doped ZnO thin film nanosensor for monitoring NO2 concentration

    Directory of Open Access Journals (Sweden)

    G.S. Hikku

    2017-07-01

    Full Text Available The metal oxide semiconductor gas sensor technology is robust and has quick response times. In this work, aluminium and tin co-doped zinc oxide (ASZO thin films were synthesized by a sol–gel dip-coating process as sensors for the greenhouse gas nitrogen dioxide (NO2. The prepared ASZO thin films were characterized using such techniques as X-ray diffraction (XRD, scanning electron microscopy (SEM, atomic force microscopy (AFM and photoluminescence (PL emission studies in order to analyze the elemental confirmation, particle size, surface roughness and optical emission properties, respectively. The XRD data reveals the hexagonal structure of ASZO and that the preferential orientation is along 2θ = 36.19°. SEM images of the ASZO thin film exhibit rod-like formations of ASZO on the substrate. The ASZO films show enhanced sensing behaviour, sensing NO2 gas even at 2 ppm at an operating temperature of 170 °C. The response and recovery times were determined to be 30 and 20 s, respectively.

  1. Rate Constant and Branching Fraction for the NH2 + NO2 Reaction

    DEFF Research Database (Denmark)

    Klippenstein, Stephen J.; Harding, Lawrence B.; Glarborg, Peter

    2013-01-01

    The NH2 + NO2 reaction has been studied experimentally and theoretically. On the basis of laser photolysis/LIF experiments, the total rate constant was determined over the temperature range 295–625 K as k1,exp(T) = 9.5 × 10–7(T/K)−2.05 exp(−404 K/T) cm3 molecule–1 s–1. This value is in the upper...... range of data reported for this temperature range. The reactions on the NH2 + NO2 potential energy surface were studied using high level ab initio transition state theory (TST) based master equation methods, yielding a rate constant of k1,theory(T) = 7.5 × 10–12(T/K)−0.172 exp(687 K/T) cm3 molecule–1 s...... with the measured overall rate constant but tend to overestimate the branching ratio defined as β = k1a/(k1a + k1b) at lower temperatures. Modest adjustments of the attractive potentials for the reaction yield values of k1a = 4.3 × 10–6(T/K)−2.191 exp(−229 K/T) cm3 molecule–1 s–1 and k1b = 1.5 × 10–12(T/K)0.032 exp...

  2. Eleven years of tropospheric NO2 measured by GOME, SCIAMACHY and OMI

    Science.gov (United States)

    Eskes, H.; Boersma, F.; Dirksen, R.; van der A, R.; Veefkind, P.; Levelt, P.; Brinksma, E.; van Roozendael, M.; de Smedt, I.; Gleason, J.

    2006-12-01

    Based on measurements of GOME on ESA ERS-2, SCIAMACHY on ESA-ENVISAT, and Ozone Monitoring Instrument (OMI) on the NASA EOS-Aura satellite there is now a unique 11-year dataset of global tropospheric nitrogen dioxide measurements from space. The retrieval approach consists of two steps. The first step is an application of the DOAS (Differential Optical Absorption Spectroscopy) approach which delivers the total absorption optical thickness along the light path (the slant column). For GOME and SCIAMACHY this is based on the DOAS implementation developed by BIRA/IASB. For OMI the DOAS implementation was developed in a collaboration between KNMI and NASA. The second retrieval step, developed at KNMI, estimates the tropospheric vertical column of NO2 based on the slant column, cloud fraction and cloud top height retrieval, stratospheric column estimates derived from a data assimilation approach and vertical profile estimates from space-time collocated profiles from the TM chemistry-transport model. The second step was applied with only minor modifications to all three instruments to generate a uniform 11-year data set. In our talk we will address the following topics: - A short summary of the retrieval approach and results - Comparisons with other retrievals - Comparisons with global and regional-scale models - OMI-SCIAMACHY and SCIAMACHY-GOME comparisons - Validation with independent measurements - Trend studies of NO2 for the past 11 years

  3. The potential for geostationary remote sensing of NO2 to improve weather prediction

    Science.gov (United States)

    Liu, X.; Mizzi, A. P.; Anderson, J. L.; Fung, I. Y.; Cohen, R. C.

    2016-12-01

    Observations of surface winds remain sparse making it challenging to simulate and predict the weather in circumstances of light winds that are most important for poor air quality. Direct measurements of short-lived chemicals from space might be a solution to this challenge. Here we investigate the application of data assimilation of NO­2 columns as will be observed from geostationary orbit to improve predictions and retrospective analysis of surface wind fields. Specifically, synthetic NO2 observations are sampled from a "nature run (NR)" regarded as the true atmosphere. Then NO2 observations are assimilated using EAKF methods into a "control run (CR)" which differs from the NR in the wind field. Wind errors are generated by introducing (1) errors in the initial conditions, (2) creating a model error by using two different formulations for the planetary boundary layer, (3) and by combining both of these effects. The assimilation reduces wind errors by up to 50%, indicating the prospects for future geostationary atmospheric composition measurements to improve weather forecasting are substantial. We also examine the assimilation sensitivity to the data assimilation window length. We find that due to the temporal heterogeneity of wind errors, the success of this application favors chemical observations of high frequency, such as those from geostationary platform. We also show the potential to improve soil moisture field by assimilating NO­2 columns.

  4. Effects of TiO2 nanoparticles on the NO2− levels in cell culture media analysed by Griess colorimetric methods

    International Nuclear Information System (INIS)

    Popescu, Traian; Lupu, Andreea R.; Diamandescu, Lucian; Tarabasanu-Mihaila, Doina; Teodorescu, Valentin S.; Raditoiu, Valentin; Purcar, Violeta; Vlaicu, Aurel M.

    2013-01-01

    The Griess assay has been used to determine the possible changes in the measured NO 2 − concentrations induced by TiO 2 nanoparticles in three types of nitrite-containing samples: aqueous NaNO 2 solutions with known concentrations, and two types of cell culture media—Roswell Park Memorial Institute medium (RPMI-1640) and Dulbecco’s Modified Eagle Medium (DMEM-F12) used either as delivered or enriched in NO 2 − by NaNO 2 addition. We have used three types of titania with average particle sizes between 10 and 30 nm: Degussa P25 and two other samples (undoped and Fe 3+ -doped anatase TiO 2 ) synthesised by a hydrothermal route in our laboratory. The structural, morphological, optical and physicochemical characteristics of the used materials have been studied by X-ray diffraction, transmission electron microscopy (EDX), Mössbauer spectroscopy, Brunauer–Emmett–Teller nitrogen adsorption, UV–Vis reflectance spectroscopy, dynamic light scattering and diffuse reflectance infrared Fourier transform spectroscopy. The opacity and sedimentation behaviour of the studied TiO 2 suspensions have been investigated by photometric attenuance measurements at 540 nm. To account for the photocatalytic properties of titania in a biologically relevant context, multiple Griess tests have been performed under controlled exposure to laboratory natural daylight illumination. The results show significant variations of light attenuance (associated with NO 2 − concentrations in the Griess test) depending on the opacity, sedimentation behaviour, NO 2 − adsorption and photocatalytic properties of the tested TiO 2 nanomaterials. These findings identify material characteristics recommended to be considered when analysing the results of Griess tests performed in biological studies involving TiO 2 nanoparticles.

  5. Using Satellite Remote Sensing and Modelling for Insights into N02 Air Pollution and NO2 Emissions

    Science.gov (United States)

    Lamsal, L. N.; Martin, R. V.; Krotkov, N. A.; Bucsela, E. J.; Celarier, E. A.; vanDonkelaar, A.; Parrish, D.

    2012-01-01

    Nitrogen oxides (NO(x)) are key actors in air quality and climate change. Satellite remote sensing of tropospheric NO2 has developed rapidly with enhanced spatial and temporal resolution since initial observations in 1995. We have developed an improved algorithm and retrieved tropospheric NO2 columns from Ozone Monitoring Instrument. Column observations of tropospheric NO2 from the nadir-viewing satellite sensors contain large contributions from the boundary layer due to strong enhancement of NO2 in the boundary layer. We infer ground-level NO2 concentrations from the OMI satellite instrument which demonstrate significant agreement with in-situ surface measurements. We examine how NO2 columns measured by satellite, ground-level NO2 derived from satellite, and NO(x) emissions obtained from bottom-up inventories relate to world's urban population. We perform inverse modeling analysis of NO2 measurements from OMI to estimate "top-down" surface NO(x) emissions, which are used to evaluate and improve "bottom-up" emission inventories. We use NO2 column observations from OMI and the relationship between NO2 columns and NO(x) emissions from a GEOS-Chem model simulation to estimate the annual change in bottom-up NO(x) emissions. The emission updates offer an improved estimate of NO(x) that are critical to our understanding of air quality, acid deposition, and climate change.

  6. [Trace elements of bone tumors].

    Science.gov (United States)

    Kalashnikov, V M; Zaĭchik, V E; Bizer, V A

    1983-01-01

    Due to activation analysis involving the use of neutrons from a nuclear reactor, the concentrations of 11 trace elements: scandium, iron, cobalt, mercury, rubidium, selenium, silver, antimony, chrome, zinc and terbium in intact bone and skeletal tumors were measured. 76 specimens of bioptates and resected material of operations for bone tumors and 10 specimens of normal bone tissue obtained in autopsies of cases of sudden death were examined. The concentrations of trace elements and their dispersion patterns in tumor tissue were found to be significantly higher than those in normal bone tissue. Also, the concentrations of some trace elements in tumor differed significantly from those in normal tissue; moreover, they were found to depend on the type and histogenesis of the neoplasm.

  7. Polar-night O3, NO2 and NO3 distributions during sudden stratospheric warmings in 2003–2008 as seen by GOMOS/Envisat

    Directory of Open Access Journals (Sweden)

    E. Kyrölä

    2012-01-01

    Full Text Available Sudden stratospheric warmings (SSW are large-scale transient events, which have a profound effect on the Northern Hemisphere stratospheric circulation in winter. During the SSW events the temperature in stratosphere increases by several tens of Kelvins and zonal winds decelerate or reverse in direction. Changes in temperature and dynamics significantly affect the chemical composition of the middle atmosphere. In this paper, the response of the middle-atmosphere trace gases during several sudden stratospheric warmings in 2003–2008 is investigated using measurements from the GOMOS (Global Ozone Monitoring by Occultation of Stars instrument on board the Envisat satellite. We have analyzed spatial and temporal changes of NO2 and NO3 in the stratosphere, and of ozone in the whole middle atmosphere. To facilitate our analyses, we have used the temperature profiles data from the MLS (Microwave Limb Sounder instrument on board the Aura satellite, as well as simulations by the FinROSE chemistry-transport model and the Sodankylä Ion and Neutral Chemistry model (SIC. NO3 observations in the polar winter stratosphere during SSWs are reported for the first time. Changes in chemical composition are found not to be restricted to the stratosphere, but to extend to mesosphere and lower thermosphere. They often exhibit a complicated structure, because the distribution of trace gases is affected by changes in both chemistry and dynamics. The tertiary ozone maximum in the mesosphere often disappears with the onset of SSW, probably because of strong mixing processes. The strong horizontal mixing with outside-vortex air is well observed also in NO2 data, especially in cases of enhanced NO2 inside the polar vortex before SSW. Almost in all of the considered events, ozone near the secondary maximum decreases with onset of SSW. In both experimental data and FinROSE modelling, ozone changes are positively correlated with temperature changes in the lower stratosphere

  8. Top-down NOX emissions over European cities from LOTOS-EUROS simulated and OMI observed tropospheric NO2 columns using the Exponentially Modified Gaussian approach

    Science.gov (United States)

    Verstraeten, Willem W.; Folkert Boersma, K.; Douros, John; Williams, Jason E.; Eskes, Henk H.; Delcloo, Andy

    2017-04-01

    High nitrogen oxides concentrations at the surface (NOX = NO + NO2) impact humans and ecosystem badly and play a key role in tropospheric chemistry. Surface NOX emissions drive major processes in regional and global chemistry transport models (CTM). NOX contributes to the formation of acid rain, act as aerosol precursors and is an important trace gas for the formation of tropospheric ozone (O3). Via tropospheric O3, NOX indirectly affects the production of the hydroxyl radical which controls the chemical lifetime of key atmospheric pollutants and reactive greenhouse gases. High NOX emissions are mainly observed in polluted regions produced by anthropogenic combustion from industrial, traffic and household activities typically observed in large and densely populated urban areas. Accurate NOX inventories are essential, but state-of the- art emission databases may vary substantially and uncertainties are high since reported emissions factors may differ in order of magnitude and more. To date, the modelled NO2 concentrations and lifetimes have large associated uncertainties due to the highly non-linear small-scale chemistry that occurs in urban areas and uncertainties in the reaction rate data, missing nitrogen (N) species and volatile organic compounds (VOC) emissions, and incomplete knowledge of nitrogen oxides chemistry. Any overestimation in the chemical lifetime may mask missing NOX chemistry in current CTM's. By simultaneously estimating both the NO2 lifetime and concentrations, for instance by using the Exponentially Modified Gaussian (EMG), a better surface NOX emission flux estimate can be obtained. Here we evaluate if the EMG methodology can reproduce the emissions input from the tropospheric NO2 columns simulated by the LOTOS-EUROS (Long Term Ozone Simulation-European Ozone Simulation) CTM model. We apply the EMG methodology on LOTOS-EUROS simulated tropospheric NO2 columns for the period April-September 2013 for 21 selected European urban areas under windy

  9. Trace Invariance for Quaternion Matrices

    Directory of Open Access Journals (Sweden)

    Ralph John de la Cruz

    2015-12-01

    Full Text Available Let F be a f ield. It is a classical result in linear algebra that for each A, P ϵ Mn (F such that P is nonsingular, tr A = tr (PAP-1. We show in this paper that the preceding property does not hold true if F is the division ring of real quaternions. We show that the only quaternion matrices that have their trace invariant under unitary similarity are Hermitian matrices, and that the only matrices that have their trace invariant under similarity are real scalar matrices.

  10. Changes in O3 and NO2 due to emissions from Fracking in the UK.

    Science.gov (United States)

    Archibald, Alexander; Ordonez, Carlos

    2016-04-01

    Poor air quality is a problem that affects millions of people around the world. Understanding the driving forces behind air pollution is complicated as the precursor gases which combine to produce air pollutants react in a highly non-linear manner and are subject to a range of atmospheric transport mechanisms compounded by the weather. A great deal of money has been spent on mitigating air pollution and so it's important to assess the impacts that new technologies that emit air pollutant precursors may have on local and regional air pollution. One of the most highly discussed new technologies that could impact air quality is the adoption of wide-scale hydraulic fracturing or "fracking" for natural gas. Indeed in regions of the USA where fracking is commonplace large levels of ozone (O3 - a key air pollutant) have been observed and attributed directly to the fracking process. In this study, a numerical modelling framework was used to assess possible impacts of fracking in the UK where at present no large scale fracking facilities are in operation. A number of emissions scenarios were developed for the principle gas phase air pollution precursors: the oxides of nitrogen (NOx) and volatile organic compounds (VOCs). These emissions scenarios were then used in a state-of-the-art numerical air quality model (the UK Met Office operational air quality forecasting model AQUM) to determine potential impacts related to fracking on UK air quality. Comparison of base model results and observations for the year 2013 of NOx, O3 and VOCs from the UK Automatic Urban and Rural Network (AURN) showed that AQUM has good skill at simulating these gas phase air pollutants (O3 r=0.64, NMGE=0.3; NO2 r=0.62, NMGE=0.51). Analysis of the simulations with fracking emissions demonstrate that there are large changes in 1hr max NO2 (11.6±6.6 ppb) with modest increases in monthly mean NO2, throughout the British Isles (150±100 ppt). These results highlight that stringent measures should be

  11. Gas phase kinetics and equilibrium of allyl radical reactions with NO and NO2.

    Science.gov (United States)

    Rissanen, Matti P; Amedro, Damien; Krasnoperov, Lev; Marshall, Paul; Timonen, Raimo S

    2013-02-07

    Allyl radical reactions with NO and NO(2) were studied in direct, time-resolved experiments in a temperature controlled tubular flow reactor connected to a laser photolysis/photoionization mass spectrometer (LP-PIMS). In the C(3)H(5) + NO reaction 1 , a dependence on the bath gas density was observed in the determined rate coefficients and pressure falloff parametrizations were performed. The obtained rate coefficients vary between 0.30-14.2 × 10(-12) cm(3) s(-1) (T = 188-363 K, p = 0.39-23.78 Torr He) and possess a negative temperature dependence. The rate coefficients of the C(3)H(5) + NO(2) reaction 2 did not show a dependence on the bath gas density in the range used (p = 0.47-3.38 Torr, T = 201-363 K), and they can be expressed as a function of temperature with k(C(3)H(5) + NO(2)) = (3.97 ± 0.84) × 10(-11) × (T/300 K) (-1.55±0.05) cm(3) s(-1). In the C(3)H(5) + NO reaction, above 410 K the observed C(3)H(5) radical signal did not decay to the signal background, indicating equilibrium between C(3)H(5) + NO and C(3)H(5)NO. This allowed the C(3)H(5) + NO ⇄ C(3)H(5)NO equilibrium to be studied and the equilibrium constants of the reaction between 414 and 500 K to be determined. With the standard second- and third-law analysis, the enthalpy and entropy of the C(3)H(5) + NO ⇄ C(3)H(5)NO reaction were obtained. Combined with the calculated standard entropy of reaction (ΔS°(298) = 137.2 J mol(-1)K(-1)), the third-law analysis resulted in ΔH°(298) = 102.4 ± 3.2 kJ mol(-1) for the C(3)H(5)-NO bond dissociation enthalpy.

  12. Posttranslational modification of bioaerosol protein by common gas pollutants: NO2 and O3

    Science.gov (United States)

    Abdullahi Mahmood, Marliyyah; Bloss, William; Pope, Francis

    2016-04-01

    Air pollution can exacerbate several medical conditions, for example, hay fever and asthma. The global incidence of hay fever has been rising for decades; however, the underlying reasons behind this rise remain unclear. It is hypothesized that the exposure of pollen to common gas phase pollutants, such as nitrogen dioxide (NO2) and ozone (O3), increases the allergenicity of the pollen and thus increases hay fever incidence (Reinmuth-Selzle et al., 2014, Franze, et al., 2005). Since atmospheric pollutants often have greater concentrations within urban areas (in particular NO2) the hypothesis suggests that greater allergenicity should occur in urban areas. Certainly, several studies do suggest higher hay fever incidence within urban areas compared to rural areas (Schröder et al., 2015). Previous published work suggests a link between increased allergies and changes in the chemical composition of pollen protein via posttranslational modification of the protein (Reinmuth-Selzle et al., 2014). This study investigates the posttranslational modification of two highly allergenic pollen species (Birch and Ragweed) that are common in Europe. Within the laboratory, we expose pollen grains to atmospherically relevant exposures of gas phase NO2, O3 and other common gas phase oxidants under a range of environmentally relevant conditions. The effects of the exposures on the biochemistry of the pollen grains were probed using a proteomic approach (liquid chromatography coupled ultra-high resolution spectrometer). Our findings indicate the interaction between gas phase pollutants and pollen cause protein specific modifications; in particular nitration that occurs upon tyrosine residues and nitrosylation on cysteine residues. These modifications may affect human immune response to the pollen protein, which may suggest a possible reason for increased allergies in reaction to such chemically altered protein. Quantification of the relative degree of PTMs, from a variety of

  13. Investigation of Simultaneous Effects of Aerosol Properties and Aerosol Peak Height on the Air Mass Factors for Space-Borne NO2 Retrievals

    Directory of Open Access Journals (Sweden)

    Hyunkee Hong

    2017-02-01

    Full Text Available We investigate the simultaneous effects of aerosol peak height (APH, aerosol properties, measurement geometry, and other factors on the air mass factor for NO2 retrieval at sites with high NO2 concentration. A comparison of the effects of high and low surface reflectance reveals that NO2 air mass factor (AMF values over a snowy surface (surface reflectance 0.8 are generally higher than those over a deciduous forest surface (surface reflectance 0.05. Under high aerosol optical depth (AOD conditions, the aerosol shielding effect over a high-albedo surface is revealed to reduce the path-length of light at the surface, whereas high single scattering albedo (SSA conditions (e.g., SSA = 0.95 lead to an increase in the aerosol albedo effect, which results in an increased AMF over areas with low surface reflectance. We also conducted an in-depth study of the APH effect on AMF. For an AOD of 0.1 and half width (HW of 5 km, NO2 AMF decreases by 29% from 1.36 to 0.96 as APH changes from 0 to 2 km. In the case of high-AOD conditions (0.9 and HW of 5 km, the NO2 AMF decreases by 240% from 1.85 to 0.54 as APH changes from 0 to 2 km. The AMF variation due to error in the model input parameters (e.g., AOD, SSA, aerosol shape, and APH is also examined. When APH is 0 km with an AOD of 0.4, SSA of 0.88, and surface reflectance of 0.05, a 30% error in AOD induces an AMF error of between 4.85% and −3.67%, an SSA error of 0.04 leads to NO2 VCD errors of between 4.46% and −4.77%, and a 30% error in AOD induces an AMF error of between −9.53% and 8.35% with an APH of 3 km. In addition to AOD and SSA, APH is an important factor in calculating AMF, due to the 2 km error in APH under high-SZA conditions, which leads to an NO2 VCD error of over 60%. Aerosol shape is also found to have a measureable effect on AMF under high-AOD and small relative azimuth angle (RAA conditions. The diurnal effect of the NO2 profile is also examined and discussed.

  14. Evolution of CH3NO2/Si interfacial chemistry under reaction conditions: a combined experimental and theoretical study.

    Science.gov (United States)

    Zhang, Xueqiang; Wang, Chen-Guang; Ji, Wei; Ptasinska, Sylwia

    2017-03-16

    Dissociative adsorption of CH 3 NO 2 onto a Si(100)-2 × 1 surface is studied using ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) and density functional theory (DFT) calculations. The unprecedented scission of the C-N bond in CH 3 NO 2 and the formation of a Si-CH 3 surface species are observed at elevated CH 3 NO 2 pressure (0.5 mbar) and temperature (>573 K).

  15. USSR Report, International Affairs Peoples of Asia and Africa No 2, March-April 1986.

    Science.gov (United States)

    1986-08-26

    Murakami Sigeyoshi (pp 166-176) (G.Ye. Svetlov) (not translated) Reviews L.A. Fridman Review of I.A. Zevelev’s ’Southeast Asia : Urbanization and...282085 JPRS-UIA-86-038 26 AUGUST 1986 USSR Report INTERNATIONAL AFFAIRS PEOPLES OF ASIA AND AFRICA No 2, MARCH-APRIL 1986 DISTRIBUTION...B* i;mited ^„> »Bpä|lf|SpI £a%Q&S; ■;.’; M*%’>’’V.i -••’::"■;• •:■■ "■• ÄÄUST 1986 USSR Report INTERNATIONAL AFFAIRS PEOPLES OF ASIA

  16. Outline of construction planning on No. 2 Reactor of the Shika Nuclear Power Plant

    International Nuclear Information System (INIS)

    Nakagawa, Tetsuro; Kadoki, Shuichi; Kubo, Tetsuji

    1999-01-01

    The Hokuriku Electric Co., Ltd. carries out the expansion of the Shika Nuclear Power Plant No.2 (ABWR) to start its in March 2006. It is situated in north neighboring side of No. 1 reactor under operation at present, and its main buildings are planned to position a reactor building at mountain side and a turbine building at sea side as well as those in the No. 1 reactor. And, cooling water for steam condenser was taken in from an intake opening built at north side of the lifting space situated at the front of the power plant, and discharged into seawater from a flashing opening positioned about 600 m offing. Here were described on outline of main civil engineering such as base excavation engineering, concrete caisson production, oceanic establishment engineering, and facility for steam condenser, and characteristics of the engineering. (G.K.)

  17. Air Emission Projections During Acid Cleaning of F-Canyon Waste Header No.2

    International Nuclear Information System (INIS)

    CHOI, ALEXANDER

    2004-01-01

    The purpose of this study was to develop the air emission projections for the maintenance operation to dissolve and flush out the scale material inside the F-Canyon Waste Header No.2. The chemical agent used for the dissolution is a concentrated nitric acid solution, so the pollutant of concern is the nitric acid vapor. Under the very conservative operating scenarios considered in this study, it was determined that the highest possible rate of nitric acid emission during the acid flush would be 0.048 lb. per hr. It turns out that this worst-case air emission projection is just below the current exemption limit of 0.05 lb. per hr. for permit applications

  18. Dose reduction and cost-benefit analysis at Japan`s Tokai No. 2 Plant

    Energy Technology Data Exchange (ETDEWEB)

    Humamoto, Hisao; Suzuki, Seishiro; Taniguchi, Kazufumi [Japan Atomic Power Co., Otemachi (Japan)

    1995-03-01

    In the Tokai No. 2 power plant of the Japan Atomic Power Company, about 80% of the annual dose equivalent is received during periodic maintenance outages. A project group for dose reduction was organized at the company`s headquarters in 1986; in 1988, they proposed a five-year program to reduce by half the collective dose of 4 person-Sv per normal outage work. To achieve the target dose value, some dose-reduction measures were undertaken, namely, permanent radiation shielding, decontamination, automatic, operating machines, and ALARA organization. As the result, the collective dose from normal outage work was 1.6 person-Sv in 1992, which was less than the initial target value.

  19. Strong-field dissociation dynamics of NO2+: A multiphoton electronic or vibrational excitation?

    Science.gov (United States)

    Jochim, Bethany; Zohrabi, M.; Ablikim, U.; Gaire, B.; Anis, F.; Carnes, K. D.; Esry, B. D.; Ben-Itzhak, I.; Wells, E.; Uhlíková, T.

    2013-05-01

    We utilize a 3-D momentum imaging technique to study laser-induced dissociation of a metastable NO2+ beam into N++ O+. Using an estimated initial vibrational population, measured kinetic energy release and angular distribution spectra, and time-dependent Schrödinger equation calculations, we identify the most likely dissociation pathways. While lower intensity pulses (process underlying this highly-aligned feature is a multiphoton permanent dipole transition solely within the electronic ground state, leading to its continuum. Supported by the DOE Chemical Sciences, Geosciences, and Biosciences Division, Office of Science. BJ also by NSF (PHY-0851599) and DOE SCGF (DE-AC05-06OR23100), BJ and EW by NSF (PHY-0969687), and TU by GACR and MetaCentrum.

  20. Unique physicochemical and catalytic properties dictated by the B3NO2 ring system

    Science.gov (United States)

    Noda, Hidetoshi; Furutachi, Makoto; Asada, Yasuko; Shibasaki, Masakatsu; Kumagai, Naoya

    2017-06-01

    The expansion of molecular diversity beyond what nature can produce is a fundamental objective in chemical sciences. Despite the rich chemistry of boron-containing heterocycles, the 1,3-dioxa-5-aza-2,4,6-triborinane (DATB) ring system, which is characterized by a six-membered B3NO2 core, remains elusive. Here, we report the synthesis of m-terphenyl-templated DATB derivatives, displaying high stability and peculiar Lewis acidity arising from the three suitably arranged boron atoms. We identify a particular utility for DATB in the dehydrative amidation of carboxylic acids and amines, a reaction of high academic and industrial importance. The three boron sites are proposed to engage in substrate assembly, lowering the entropic cost of the transition state, in contrast with the operative mechanism of previously reported catalysts and amide coupling reagents. The distinct mechanistic pathway dictated by the DATB core will advance not only such amidations, but also other reactions driven by multisite activation.

  1. Staff Rules & Regulations – modification No. 2 to the 11th Edition

    CERN Multimedia

    HR Department

    2008-01-01

    In June 2008, the Finance Committee and the Council approved the following amendments to the Staff Rules and Regulations:Chapter II, Conditions of Employment and Association, Section 4 (Leave): page 26 has been amended - with effect from 1 July 2008;Chapter III, Working Conditions, Section 1 (Working Hours): pages 30 to 32 have been amended and pages 33 and 34 have been deleted – with effect from 1 July 2008. Modification No. 2 is available from departmental secretariats (paper copies), or from the HR Department’s intranet site. In accordance with the above-mentioned amendments, the deleted parts of Chapter III will appear in the relevant administrative circulars. Until the revision of the latter (currently in process) is completed, the deleted parts of Chapter III continue to apply in accordance with transition measures decided by the Director-General. Please note that modification No. 1, concerning amendments approved by the Council in June 2007 to Annexes A 1 and corr...

  2. On the temperature dependence of the reaction O+NO-NO2(asterisk). [in earth atmosphere

    Science.gov (United States)

    Sharp, W. E.

    1984-01-01

    The published data on the temperature dependence of the radiative combination of atomic oxygen with nitric oxide at pressures near 1 torr is examined. Arguments are advanced to suggest that radiation near the cut-off wavelength (about 3875A) is coming from the unstabilized activated complex, NO2(asterisk). At 4000A a positive activation energy of 1 kcal/mole is deduced. Application of this temperature dependence with the rate coefficient at 5200A is made to airglow measurements in aurora. The deduced NO concentration is about 10 to the 9th per cu cm, in general agreement with that deduced from the measured NO(+)/O2(+) ratio as well as an auroral model prediction.

  3. Deviations from the O3-NO-NO2 photo-stationary state in Delhi, India

    Science.gov (United States)

    Chate, Dilip M.; Ghude, Sachin D.; Beig, Gurfan; Mahajan, Anoop S.; Jena, Chinmay; Srinivas, Reka; Dahiya, Anita; Kumar, Nandini

    2014-10-01

    A network of air quality and weather monitoring stations was set-up across Delhi, India, under the System of Air quality Forecasting And Research (SAFAR) project. The objective of this network was to enable better understanding of air quality in terms of atmospheric chemistry, emissions and forecasting in Delhi, one of the largest metropolises in the world. In this study, we focus on the O3-NO-NO2-triad Photo Stationary State (PSS), and investigate site-specific deviations in the Leighton Ratio (Φ) during a short period in 2012 (1-31 December). Large variations were observed in the NO ( 1) were also observed occasionally, and these data were used to estimate the total peroxy radical (PO2) mixing ratios. This is the first estimate of PO2 reported for the city of Delhi and compares well with the results in the literature.

  4. Effects of No. 2 fuel oil on hatchability of marine and estuarine bird eggs

    Science.gov (United States)

    White, Donald H.; King, Kirke A.; Coon, Nancy C.

    1979-01-01

    Oil spills and discharges may kill birds directly by destroying the insulation that their feathers provide so that they die of exposure; by poisoning them if they ingest oil; and by stressing them so that they starve to death. But oil pollution has more subtle effects, too. Nesting birds exposed to sublethal quantities of oil may transfer the oil to eggs in their nests, thereby causing failure of the eggs to hatch (RITTINGHAUS 1956). Laboratory studies have shown that very small quantities of oil, when applied to eggs of waterfowl, significantly reduced hatchability (HARTUNG 1965, ALBERS 1977a, SZARO and ALBERS 1977). The objective of this study was to determine the effects of external applications of No. 2 fuel oil on embryo survival of naturally and of artificially incubated eggs of marine and estuarine birds.

  5. Ship emissions of SO2 and NO2: DOAS measurements from airborne platforms

    Directory of Open Access Journals (Sweden)

    J.-P. Jalkanen

    2012-05-01

    Full Text Available A unique methodology to measure gas fluxes of SO2 and NO2 from ships using optical remote sensing is described and demonstrated in a feasibility study. The measurement system is based on Differential Optical Absorption Spectroscopy using reflected skylight from the water surface as light source. A grating spectrometer records spectra around 311 nm and 440 nm, respectively, with the telescope pointed downward at a 30° angle from the horizon. The mass column values of SO2 and NO2 are retrieved from each spectrum and integrated across the plume. A simple geometric approximation is used to calculate the optical path. To obtain the total emission in kg h−1 the resulting total mass across the plume is multiplied with the apparent wind, i.e. a dilution factor corresponding to the vector between the wind and the ship speed. The system was tested in two feasibility studies in the Baltic Sea and Kattegat, from a CASA-212 airplane in 2008 and in the North Sea outside Rotterdam from a Dauphin helicopter in an EU campaign in 2009. In the Baltic Sea the average SO2 emission out of 22 ships was (54 ± 13 kg h−1, and the average NO2 emission was (33 ± 8 kg h−1, out of 13 ships. In the North Sea the average SO2 emission out of 21 ships was (42 ± 11 kg h−1, NO2 was not measured here. The detection limit of the system made it possible to detect SO2 in the ship plumes in 60% of the measurements when the described method was used. A comparison exercise was carried out by conducting airborne optical measurements on a passenger ferry in parallel with onboard measurements. The comparison shows agreement of (−30 ± 14% and (−41 ± 11%, respectively, for two days, with equal measurement precision of about 20%. This gives an idea of the measurement uncertainty caused by errors in the simple geometric approximation for the optical light path neglecting scattering of the light in ocean waves and direct and multiple scattering in the exhaust plume under

  6. Modeling annual benzene, toluene, NO2, and soot concentrations on the basis of road traffic characteristics

    International Nuclear Information System (INIS)

    Carr, David; Ehrenstein, Ondine von; Weiland, Stephan; Wagner, Claudia; Wellie, Oliver; Nicolai, Thomas; Mutius, Erika von

    2002-01-01

    The investigation of potential adverse health effects of urban traffic-related air pollution is hampered by difficulties encountered with exposure assessment. Usually public measuring sites are few and thereby do not adequately describe spatial variation of pollutant levels over an urban area. In turn, individual monitoring of pollution exposure among study subjects is laborious and expensive. We therefore investigated whether traffic characteristics can be used to adequately predict benzene, NO 2 , and soot concentrations at individual addresses of study subjects in the city area of Munich, Germany. For all road segments with expected traffic volumes of at least 4000 vehicles a day (n=1840), all vehicles were counted manually or a single weekday in 1995. The proportion of vehicles in 'stop-go' mode, n estimate of traffic jam, was determined. Furthermore, annual concentrations of benzene, NO 2 , and soot from 18 high-concentration sites means: 8.7, 65.8, and 12.9 μg/m 3 , respectively) and from 16 school sites with moderate concentrations (means: 2.6, 32.2, and 5.7 μg/m 3 , respectively) were measured from 1996 to 1998. Statistical analysis of the data was performed using components of two different statistical models recently used to predict air pollution levels in comparable settings. Two traffic characteristics, traffic volume and traffic jam percentage, adequately described air pollutant concentrations (R 2 : 0.76-0.80, P=0.0001). This study shows that air pollutant concentrations can be accurately predicted by two traffic characteristics and that these models compare favorably with other more complex models in the literature

  7. Driver exposure to volatile organic compounds, CO, ozone, and NO2 under different driving conditions

    International Nuclear Information System (INIS)

    Changchuan Chan; Oezkaynak, H.; Spengler, J.D.; Sheldon, L.

    1991-01-01

    The in-vehicle concentrations of 24 gasoline-related volatile organic compounds (VOCs) and three criteria air pollutants, ozone, carbon monoxide, and nitrogen dioxide, were measured in the summer of 1988, in Raleigh, NC. Two four-door sedan of different ages were used to evaluate in-vehicle concentrations of these compounds under different driving conditions. Factors that could influence driver exposure, such as different traffic patterns, car model, vehicle ventilation conditions, and driving periods, were evaluated. Isopentane was the most abundant aliphatic hydrocarbon and toluene was the most abundant aromatic VOC measured inside the vehicles. In-vehicle VOC and CO concentrations were highest for the urban roadway, second highest for the interstate highway, and lowest for the rural road. The median concentration ratio of urban/interstate/rural for each VOC was about 10/6/1. No differences in in-vehicle VOC concentrations were found between morning and afternoon rush hour driving, but higher in-vehicle ozone and NO 2 concentrations were found during afternoon driving. In-vehicle VOC levels were lowest with the air conditioner on and highest when the vent was open with the fan on. The in-vehicle/car exterior concentration ratio for VOCs, CO, and NO 2 was slightly higher than 1. The VOC concentration measured by a pedestrian on the urban sidewalk was lower than the in-vehicle measurements but higher than the fixed-site measurements but higher than the fixed-site measurements on urban roadways 50 m from streets. The VOC measurements were positively correlated with the CO measurement and negatively correlated with the ozone measurement

  8. Estimates of Lightning NOx Production Based on OMI NO2 Observations Over the Gulf of Mexico

    Science.gov (United States)

    Pickering, Kenneth E.; Bucsela, Eric; Allen, Dale; Ring, Allison; Holzworth, Robert; Krotkov, Nickolay

    2016-01-01

    We evaluate nitrogen oxide (NO(sub x) NO + NO2) production from lightning over the Gulf of Mexico region using data from the Ozone Monitoring Instrument (OMI) aboard NASAs Aura satellite along with detection efficiency-adjusted lightning data from the World Wide Lightning Location Network (WWLLN). A special algorithm was developed to retrieve the lightning NOx [(LNO(sub x)] signal from OMI. The algorithm in its general form takes the total slant column NO2 from OMI and removes the stratospheric contribution and tropospheric background and includes an air mass factor appropriate for the profile of lightning NO(sub x) to convert the slant column LNO2 to a vertical column of LNO(sub x). WWLLN flashes are totaled over a period of 3 h prior to OMI overpass, which is the time an air parcel is expected to remain in a 1 deg. x 1 deg. grid box. The analysis is conducted for grid cells containing flash counts greater than a threshold value of 3000 flashes that yields an expected LNO(sub x) signal greater than the background. Pixels with cloud radiance fraction greater than a criterion value (0.9) indicative of highly reflective clouds are used. Results for the summer seasons during 2007-2011 yield mean LNO(sub x) production of approximately 80 +/- 45 mol per flash over the region for the two analysis methods after accounting for biases and uncertainties in the estimation method. These results are consistent with literature estimates and more robust than many prior estimates due to the large number of storms considered but are sensitive to several substantial sources of uncertainty.

  9. Separation of 15N by isotopic exchange in NO, NO2-HNO3 system under pressure

    International Nuclear Information System (INIS)

    Axente, D.; Baldea, A.; Teaca, C.; Horga, R.; Abrudean, M.

    1998-01-01

    One of the most used method for production of 15 N with 99% at. concentration is the isotopic exchange between gaseous nitrogen oxides and HNO 3 solution 10M: ( 15 NO, 15 NO 2 ) g + H 14 NO 3,l = ( 14 NO, 14 NO 2 ) g + H 15 NO 3,l . The isotopic exchange is characterized by an elemental separation factor α=1.055 at 25 deg. C and atmospheric pressure. Recently, kinetics data pointed to the linear dependence of the exchange rate 15 N/ 14 N(R) on the nitrogen oxide pressure with a rate law R = k[HNO 3 ] 2 · [N 2 O 3 ]. In this work, the influence of the nitrogen oxide pressure on the 15 N separation efficiency was determined by the use of a laboratory equipment with a separation column pack of Helipack type, with dimensions 1.8 mm x 1.8 mm x 0.2 mm. The increase of nitrogen oxide pressure led to a better isotopic transfer between the two counter-flow phases in the column pack. The HETP (Height Equivalent to a Theoretical Plate) determined for a 3.14 ml ·cm -2 · min -1 load is equal to that obtained at atmospheric pressure for a two times lower load. The operation of the equipment for isotopic separation of 15 N at 1.8 atm instead of atmospheric pressure allows doubling the HNO 3 10 M load of the column and consequently, doubling the production rate. A better performance of the separation process at higher pressure is essential for the industrial production of 15 N isotope which is used for the production of uranium nitride in FBR type reactors. (authors)

  10. Diamond field-effect transistors for RF power electronics: Novel NO2 hole doping and low-temperature deposited Al2O3 passivation

    Science.gov (United States)

    Kasu, Makoto

    2017-01-01

    Diamond possesses a combination of exceptional physical properties and is expected to be used as a semiconductor material in high-efficiency and high-power electronic devices. In this study, hole doping was observed when using NO2 molecules on a H-diamond surface. The activation energy of hole concentration in NO2/H-diamond was measured as 0.006 eV, and holes were fully activated at room temperature. A thermal stabilization of the hole channel was realized by passivation with an atomic-layer-deposited Al2O3 layer. The passivation method enabled the realization of a thermally stable high-performance diamond field-effect transistor (FET), which exhibited high-performance DC and RF characteristics. NO2 hole-doping and Al2O3-passivation technologies enabled reproducible measurements of MOS structure electric properties. Such technologies also facilitated observations of two-dimensional holes at the MOS interface and type-II band alignment of Al2O3/NO2/H-diamond. Additionally, the band diagram under various gate bias conditions was proposed on the basis of capacitance-voltage measurements and analysis using Poisson’s equations.

  11. SPECTROPHOTOMETRIC DETERMINATION OF TRACE OXALIC ...

    African Journals Online (AJOL)

    Based on the property that oxalic acid has the effect on the replacement of dibromochloroarsenazo in zirconium(IV)-dibromochloroarsenazo complex to produce hyperchromic effects in 1.26 M hydrochloric acid medium, a novel method for the determination of trace oxalic acid by spectrophotometry was developed.

  12. Trace elements in brazilian soils

    International Nuclear Information System (INIS)

    Rocha, Geraldo Cesar

    1995-01-01

    A literature revision on trace elements (Zn, B, Mn, Mo, Cu, Fe, and Cl) in Brazilian soils was prepared, with special attention to the chemical form and range in the soil, extraction methods and correlation of the amount in soils with soil properties

  13. Investigation of trace element mobility in river sediments using ICP ...

    African Journals Online (AJOL)

    In this study, the column method was used to determine the leachable trace metals present in selected river sediments. In addition the sediments were investigated using a shaker method and these two methods were compared for reliability. For both these methods extract solutions associated with a sequential extraction ...

  14. Coagulation / flocculation process in the removal of trace metals ...

    African Journals Online (AJOL)

    Attempts were made in this study to examine the effectiveness of polymer addition to coagulation process during treatment of a beverage industrial wastewater to remove some of its trace metals content such as lead, cadmium, total iron, total chromium, nickel and zinc. Experiments were conducted using the standard Jar ...

  15. Ultra-Trace Analysis of Krypton-85

    International Nuclear Information System (INIS)

    Daerr, H.; Kalinowski, M.; Kohler, M.; Sahling, P.

    2010-01-01

    To strengthen the efficiency and effectiveness of nuclear safeguards for detecting undeclared nuclear material and activities we propose to use the radioactive krypton isotope Krypton-85 as a tracer for clandestine plutonium production. The main idea is to detect inexplicable atmospheric Kr85 concentration using the novel technology atom trap trace analysis (ATTA) in order to detect an undeclared reprocessing facility. The Additional Protocol (INFCIRC/540, 1997) establishes the possibility to take environmental samples. Krypton-85 has a combination of unique features which makes it an ideal tracer for plutonium separation activities anywhere in the world. It is always generated along with plutonium and 99.9% remains within the fuel cladding. Due to its half-life of 10.76 years, significant amounts of krypton-85 still remain in the spent fuel even after long cooling times. Krypton is not removed from the atmosphere by any processes like chemical reactions or wash-out. Furthermore, there are no other relevant sources of krypton-85 besides of reprocessing. The novel technology of atom trap trace analysis (ATTA) has been demonstrated by the physics group at Argonne National Laboratory in 1999. This is an ultra-sensitive trace analysis technique able to detect single krypton atoms. We are setting up an ATTA apparatus in our laboratory, which is designed to fulfill all requirements to detect clandestine plutonium production. Our goal is to determine Krypton-85 concentration of one liter samples of atmospheric air with an analysis time of 3 hours. This sample volume reduction is a significant step, since one liter can be taken as a grab sample by sucking it directly into pre-evacuated bottles at atmospheric pressure. The small samples size and the short analysis time of ATTA will make it possible to use krypton-85 as a tracer for clandestine plutonium production with routine operation. (author)

  16. Tracing Magnetic Fields with Spectroscopic Channel Maps

    Science.gov (United States)

    Lazarian, A.; Yuen, Ka Ho

    2018-01-01

    We identify velocity channel map intensities as a new way to trace magnetic fields in turbulent media. This work makes use of both the modern theory of magnetohydrodynamic (MHD) turbulence, which predicts that magnetic eddies are aligned with the local direction of the magnetic field, and also the theory of spectral line position–position–velocity (PPV) statistics, which describes how velocity and density fluctuations are mapped onto PPV space. In particular, we use the fact that the fluctuations of the intensity of thin channel maps are mostly affected by the turbulent velocity, while the thick maps are dominated by density variations. We study how contributions of the fundamental MHD modes affect the Velocity Channel Gradients (VChGs), and demonstrate that the VChGs arising from Alfvén and slow modes are aligned perpendicular to the local direction of the magnetic field, while the VChGs produced by the fast mode are aligned parallel to the magnetic field. The dominance of Alfvén and slow modes in interstellar media will therefore allow reliable magnetic field tracing using the VChGs. We explore ways of identifying self-gravitating regions that do not require polarimetric information. In addition, we also introduce a new measure, termed “Reduced Velocity Centroids” (RVCGs), and compare its abilities with those of VChGs. We employed VChGs in analyzing GALFA 21 cm data and successfully compared the magnetic field directions with the Planck polarization observations. The applications of the suggested techniques include both tracing the magnetic field in diffuse interstellar media and star-forming regions, and removing the galactic foreground in the framework of cosmological polarization studies.

  17. Trace-Element Analyses of Carbonate Minerals in the Gunflint Banded Iron Formation

    Science.gov (United States)

    Pun, Aurora; Papike, James J.; Shearer, C. K.

    2002-01-01

    We report on the petrography, mineralogy and trace-element abundances of individual carbonate grains in the Early Proterozoic Gunflint BIF (Banded Iron Formation). Trace-element data may be used as environmental recorders of the fluid evolution from which the various carbonate phases precipitated. Additional information is contained in the original extended abstract.

  18. Gate-bias controlled charge trapping as a mechanism for NO2 detection with field-effect transistors

    NARCIS (Netherlands)

    Andringa, A.-M.; Meijboom, J.R.; Smits, E.C.P.; Mathijssen, S.G.J.; Blom, P.W.M.; Leeuw, D.M. de

    2011-01-01

    Detection of nitrogen dioxide, NO2, is required to monitor the air-quality for human health and safety. Commercial sensors are typically chemiresistors, however field-effect transistors are being investigated. Although numerous investigations have been reported, the NO2 sensing mechanism is not

  19. Gate-Bias Controlled Charge Trapping as a Mechanism for NO2 Detection with Field-Effect Transistors

    NARCIS (Netherlands)

    Andringa, Anne-Marije; Meijboom, Juliaan R.; Smits, Edsger C. P.; Mathijssen, Simon G. J.; Blom, Paul W. M.; de Leeuw, Dago M.

    2011-01-01

    Detection of nitrogen dioxide, NO2, is required to monitor the air-quality for human health and safety. Commercial sensors are typically chemiresistors, however field-effect transistors are being investigated. Although numerous investigations have been reported, the NO2 sensing mechanism is not

  20. 76 FR 38381 - Public Utility District No. 2 of Grant County; Notice of Availability of Environmental Assessment

    Science.gov (United States)

    2011-06-30

    ... Energy Regulatory Commission Public Utility District No. 2 of Grant County; Notice of Availability of... Regulatory Commission's regulations, 18 CFR part 380, the Office of Energy Projects has reviewed Public Utility District No. 2 of Grant County's proposed shoreline management plan (SMP) for the Priest Rapids...

  1. 78 FR 34360 - Public Utility District No. 2 of Grant County, Washington; Notice of Application Accepted for...

    Science.gov (United States)

    2013-06-07

    ... Energy Regulatory Commission Public Utility District No. 2 of Grant County, Washington; Notice of.... Date Filed: November 27, 2013. d. Applicant: Public Utility District No. 2 of Grant County, Washington... the following hydroelectric application has been filed with the Commission and is available for public...

  2. Quantum Yields of Nitrite (NO2-) from the Photolysis of Nitrate (NO3-) in Ice at 313 nm.

    Science.gov (United States)

    Benedict, Katherine B; Anastasio, Cort

    2017-11-09

    Photochemical reactions of nitrate in snow release reactive nitrogen species via two channels, which produce (1) nitrogen dioxide (NO 2 ) and hydroxyl radical ( • OH) and (2) nitrite (NO 2 - ) and oxygen atom (O( 3 P)). Quantum yields (Φ) for these channels are generally well characterized, except for channel 2 in ice. In this study, we quantify Φ(NO 2 - ) in water ices and examine the impacts of pH and organic scavengers of • OH. Compared to solution results, we find that nitrite quantum yields in ice are more sensitive to pH and that • OH scavengers are less effective, although 2-propanol appears to work well. The temperature dependence (-30 to 25 °C) of Φ(NO 2 - ) in samples containing 2-propanol is well described by a single regression line, ln(Φ(NO 2 - )) = -(1330 ± 100)(1/T(K)) + (0.09 ± 0.39). At -10 °C, the resulting quantum yield is 4.6 times larger than the previously reported (and recommended) value without an • OH scavenger. Although some reports suggest nitrite is a minor product from nitrate photolysis, based on our current and past results, rates of photoproduction of NO 2 - and NO 2 are similar at room temperature, while NO 2 - production dominates at lower temperatures in solution and ice.

  3. Trace spaces in a pre-cubical complex

    DEFF Research Database (Denmark)

    Raussen, Martin

    arc length which moreover is shown to be invariant under directed homotopies. D-paths up to reparametrization (called traces) can thus be represented by arc length parametrized d-paths. Under weak additional conditions,it is shown that trace spaces in a pre-cubical complex are separable metric spaces......In directed algebraic topology, (spaces of) directed irreversible (d)-paths are studied from a topological and from a categorical point of view. Motivated by models for concurrent computation, we study in this paper spaces of d-paths in a pre-cubical complex. Such paths are equipped with a natural...

  4. Trace spaces in a pre-cubical complex

    DEFF Research Database (Denmark)

    Raussen, Martin

    2009-01-01

    In directed algebraic topology, directed irreversible (d)-paths and spaces consisting of d-paths are studied from a topological and from a categorical point of view. Motivated by models for concurrent computation, we study in this paper spaces of d-paths in a pre-cubical complex. Such paths...... are equipped with a natural arc length which moreover is shown to be invariant under directed homotopies. D-paths up to reparametrization (called traces) can thus be represented by arc length parametrized d-paths. Under weak additional conditions, it is shown that trace spaces in a pre-cubical complex...

  5. Model simulation of NO3, N2O5 and ClNO2 at a rural site in Beijing during CAREBeijing-2006

    Science.gov (United States)

    Wang, Haichao; Lu, Keding; Tan, Zhaofeng; Sun, Kang; Li, Xin; Hu, Min; Shao, Min; Zeng, Limin; Zhu, Tong; Zhang, Yuanhang

    2017-11-01

    A chemical box model was used to study nitrate radical (NO3), dinitrogen pentoxide (N2O5) and nitryl chloride (ClNO2) in a rural site during the Campaign of Air Quality Research in Beijing 2006 (CAREBeijing-2006). The model was based on regional atmospheric chemistry mechanism version 2 (RACM2) with the heterogeneous uptake of N2O5 and the simplified chloride radical (Cl) chemistry mechanism. A high production rate of NO3 with a mean value of 0.8 ppbv/h and low mixing ratios of NO3 and N2O5 (peak values of 17 pptv and 480 pptv, respectively) existed in this site. Budget analysis showed that NO emission suppressed the NO3 chemistry at the surface layer, the reaction of NO3 with VOCs made a similar contribution to NO3 loss as N2O5 heterogeneous uptake. The NO3 chemistry was predominantly controlled by isoprene, and NO3 oxidation produced organic nitrate with a mean value of 0.06 ppbv/h during nighttime. The organic nitrate production initiated by NO3 was equal to that initiated by OH, implying the importance of nighttime chemistry for secondary organic aerosol (SOA) formation. We confirmed that the N2O5 heterogeneous reaction accounted for nighttime particle NO3- enhancement, with a large day to day variability, and made less of a contribution to NOx loss compared to that of OH reacting with NO2. Additionally, abundant ClNO2, up to 5.0 ppbv, was formed by N2O5 heterogeneous uptake. ClNO2 was sustained at a high level until noon in spite of the gradually increasing photolysis of ClNO2 after sunrise. Chlorine activation caused by N2O5 heterogeneous uptake increased primary ROx formation by 5% and accounted for 8% of the net ozone production enhancement in the morning.

  6. Natural wetland emissions of methylated trace elements

    NARCIS (Netherlands)

    Vriens, B.; Lenz, M.; Charlet, L.; Berg, M.; Winkel, L.H.E.

    2014-01-01

    Natural wetlands are well known for their significant methane emissions. However, trace element emissions via biomethylation and subsequent volatilization from pristine wetlands are virtually unstudied, even though wetlands constitute large reservoirs for trace elements. Here we show that the

  7. Screen printed In2O3-SnO2 nanocomposite: Structural and morphological properties and application for NO2 detection

    Directory of Open Access Journals (Sweden)

    Bessaïs B.

    2012-06-01

    Full Text Available In this work, we report on the sensing properties of screen-printed In2O3 (Indium Oxide while adding a moderate quantity of SnO2. It was found that the addition of SnO2 improves the response and decreases the operating temperature of the sensitive element for NO2 detection. However, a non-controlled amount of SnO2 leads to opposite result; for this reason in the present investigation we test films with different composition in order to optimize the quantity of SnO2 to be added. The crystallinity, roughness and morphology of the obtained In2O3-SnO2 anocomposite were analyzed using X-ray Diffraction (XRD, Transmission Electronic Microscopy (TEM and Atomic Force Microscopy (AFM. The atomic composition of the In2O3-SnO2 films was determined with the energy dispersive spectroscopy (EDX analysis during TEM observations. The effect of the composition on the cristallinity and morphological properties of the films was analyzed. Finally, the In2O3-SnO2 films were tested like sensitive elements for NO2 detection, wherein the effect of the composition was correlated with the sensor response in NO2 ambient. It was found that the addition of a moderate quantity of SnO2 to In2O3 exhibited high sensitivity at rather lower operating temperatures.

  8. Sea-water intake tower works for Hamaoka Nuclear Power Station No. 2 Plant

    International Nuclear Information System (INIS)

    Satake, Norimoto; Sugaya, Yoshinobu; Sugimoto, Tadao

    1976-01-01

    It was determined to adopt tunnel system based on the conclusion of negotiation with local people, specifically fishermen, for the sea water intake arrangement in Hamaoka Nuclear Power Station. The main factors for determining the location of the intake tower included marine conditions such as waves and littoral sand drift, and the sea-bottom topographic features and geology of tunnel route, for which field examination, hydraulic experiments and the research and investigation on the method of construction were carried out. These results in the No.2 tower installation at the point 65 m to the east of the No.1 tower. The construction of the tower is described on the manufacture and conveyance of steel caisson, land works at Omaezaki and temporary assembly works on the sea. Then the details of tower installation and the works on site are reported. Fortunately the difficult sea works have been satisfactorily completed earlier than planned, without any accident. The construction facilities utilizing a pilot tunnel seem to have made the better achievement than expected. In spite of the results, the lifting up, off-shore conveyance, and installation of the intake tower caisson, a superheavy structure of weighting up to total 2900 ton, were critical works. (Wakatsuki, Y.)

  9. Office for Analysis and Evaluation of Operational Data. 1992 annual report: Nonreactors: Volume 7, No. 2

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    The annual report of the US Nuclear Regulatory Commission`s Office for Analysis and Evaluation of Operational Data (AEOD) is devoted to the activities performed during 1992. The report is published in two separate parts. NUREG-1272, Vol. 7, No. 1, covers power reactors and presents an overview of the operating experience of the nuclear power industry from the NRC perspective, including comments about the trends of some key performance measures. The report also includes the principal findings and issues identified in AEOD studies over the past year and summarizes information from such sources as licensee event reports, diagnostic evaluations, and reports to the NRC`s Operations Center. NUREG-1272, Vol. 7, No. 2, covers nonreactors and presents a review of the events and concerns during 1992 associated with the use of licensed material in nonreactor applications, such as personnel overexposures and medical misadministrations. Both reports also contain a discussion of the Incident Investigation Team program and summarize both the Incident Investigation Team and Augmented Inspection Team reports. Each volume contains a list of the AEOD reports issued for 1981--1992.

  10. Crown Zellerbach Well No. 2, Livingston Parish, Louisiana. Volume I. Completion and testing. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The Crown Zellerbach Well No. 2, approximately 23 miles east of Baton Rouge, Louisiana, is the eighth successful test of a geopressured-geothermal aquifer under the DOE Wells of Opportunity program. The well was tested through the annulus between 7-inch casing and 2-3/8 inch tubing. Two flow tests and one reservoir pressure buildup test were conducted on the lower zone during a 13-day period. A total of 12,489 barrels of water was produced. The highest flow rate achieved was about 3887 BWPD. One flow test followed by a buildup period was conducted on the combined upper and lower zones during a 3-day period. A total of 4739 barrels of water was produced. The highest flow rate achieved was about 3000 BWPD. The gas/water ratio measured during testing was about 32.0 SCF/BBL for the lower zone. The extrapolated latoratory data indicates that the solubility of the gas is 55.7 SCF/BBL. It appears that the reservoir brine is considerably undersaturated. The methane content of the flare line gas averaged 71.0 mole percent. Crown Zellerbach Company carefully studied the commercial feasibility of using the well to produce energy for a wood-drying facility and decided against the project.

  11. Ba-Doped Iron Oxide as a New Material for NO2 Detection

    Directory of Open Access Journals (Sweden)

    Jean-Marc Tulliani

    2013-10-01

    Full Text Available Various compositions of barium-doped hematite between pure hematite (α-Fe2O3 and pure barium hexaferrite (BaFe12O19 were synthesized by solid state reaction. The XRD analyses confirmed the progressive evolution of the two crystalline phases. Tests as humidity sensors show that the electrical resistance of samples containing high proportions of hexaferrite phase is strongly influenced. Electrochemical impedance spectroscopy (EIS analyses under air or argon revealed an intrinsic semiconducting behavior for hematite and samples doped with 3 and 4 wt % equivalent BaO. The samples containing higher proportions of barium exhibited an extrinsic semiconducting behavior characterized by a variation of the conductivity with the oxygen partial pressure. This study allowed us to define the percolation threshold of the barium hexaferrite crystalline phase in the hematite matrix. The value was estimated to hematite doped with 5 wt % BaO, i.e., 36 wt % of barium hexaferrite phase. EIS analyses under various NO2 partial pressures confirmed the sensitivity of these materials. The linearity of the response was particularly evident for the 5, 10 and 14 wt % samples.

  12. Examination of the SG tube fatigue cracking at Fessenheim unit no.2 of EDF

    International Nuclear Information System (INIS)

    Boccanfuso, M.; Lorthios, J.; Thebault, Y.; Bruyere, B.; Duisabeau, L.; Herms, E.

    2015-01-01

    In February 2008, a primary-to-secondary leak occurred at Fessenheim Unit No.2 on a steam generator. A circumferential fatigue crack was observed at the upper tube support plate level of the R12C62 tube although the stability ratio evaluation performed to take into account some prior international events, concluded that this tube had no risk of fluid-elastic instability. A new tube pull process was developed and performed by AREVA in 2011 just before the SG replacement. The extraction at the uppermost TSP elevation was a first occurrence in the French EDF PWR. Destructive examinations were carried out in the EDF hot laboratory of CEIDRE/Chinon in order to characterize damage mechanisms at the initiation and propagation stage. The document relates the major results of laboratory examinations leading us to exclude the fluid-elastic instability scenario as previously reported in North-Anna (1987) and Mihama (1991) tube rupture incidents. Results analysis with particular focus on the fracture surface description using Scanning Electron microscopy observations and metallurgical investigations provide new elements concerning the aggravating factors of fatigue damage. Fracture surface investigations reveal that the circumferential crack was due to high cycle fatigue with a very low stress intensity factor. Some aggravating factors like intergranular corrosion appeared to be critical for the fatigue cracking initiation stage. The deterioration was also largely promoted by the lack of tube support at the Anti-Vibration Bars

  13. Three-Dimensional Crumpled Graphene-Based Nanosheets with Ultrahigh NO2Gas Sensibility.

    Science.gov (United States)

    Chen, Zhuo; Wang, Jinrong; Umar, Ahmad; Wang, Yao; Li, Hao; Zhou, Guofu

    2017-04-05

    It is well-established that the structures dominate the properties. Inspired by the highly contorted and crumpled maxilloturbinate inside dog nose, herein an artificial nanostructure, i.e., 3D crumpled graphene-based nanosheets, is reported with the simple fabrication, detailed characterizations, and efficient gas-sensing applications. A facile supramolecular noncovalent assembly is introduced to modify graphene with functional molecules, followed with a lyophilization process to massively transform 2D plane graphene-based nanosheets to 3D crumpled structure. The detailed morphological characterizations reveal that the bioinspired nanosheets exhibit full consistency with maxilloturbinate. The fabricated 3D crumpled graphene-based sensors exhibit ultrahigh response (R a /R g = 3.8) toward 10 ppm of NO 2 , which is mainly attributed to the specific maxilloturbinate-mimic structure. The sensors also exhibit excellent selectivity and sensing linearity, reliable repeatability, and stability. Interestingly, it is observed that only 4 mg of graphene oxide (GO) raw materials can produce more than 1000 gas sensors, which provides a new insight for developing novel 3D biomimetic materials in large-scale gas sensor production.

  14. Theoretical study of the D-->C emission spectrum of NO(2).

    Science.gov (United States)

    Schinke, R

    2008-09-28

    The 3 (2)A(')(D)-->1 (2)A(")(C) emission spectrum of NO(2) has been calculated by means of exact dynamics calculations and an accurate potential energy surface for the C state. The potential energy surface has been obtained by electronic structure calculations employing the internally contracted multireference configuration interaction method plus Davidson correction and the augmented correlation consistent polarized quadruple zeta basis set. The calculated spectrum, based on energies as well as intensities, agrees well with the measured one. Despite the two asymmetric C(s) potential wells of the C potential energy surface, the spectrum is best described by a C(2v) assignment in terms of symmetric stretch, bending, and antisymmetric stretch quantum numbers. The barrier separating the two wells is merely of the order of 500 cm(-1) with the consequence that only the two lowest states, (0,0,0) and (0,0,1), show a tunneling splitting. Essential for the correct assignment of the spectrum is the pronounced negative anharmonicity of the antisymmetric stretch mode. Excitation of the symmetric stretch mode is not directly seen in the main part of the spectrum.

  15. Numerical modeling of the Near Surface Test Facility No. 1 and No. 2 heater tests

    International Nuclear Information System (INIS)

    Hocking, G.; Williams, J.; Boonlualohr, P.; Mathews, I.; Mustoe, G.

    1981-01-01

    Thermomechanical predictive calculations have been undertaken for two full scale heater tests No. 1 and No. 2 at the Near Surface Test Facility (NSTF) at Hanford, Washington. Numerical predictions were made of the basaltic rock response involving temperatures, displacements, strains and stresses due to energizing the electrical heaters. The basalt rock mass was modeled as an isotropic thermal material but with temperature dependent thermal conductivity, specific heat and thermal expansion. The fractured nature of the basalt necessitated that it be modeled as a cross anisotropic medium with a bi-linear locking stress strain relationship. The cross-anisotropic idealization was selected after characterization studies indicated that a vertical columnar structure persisted throughout the test area and no major throughgoing discontinuities were present. The deformational properties were determined from fracture frequency and orientation, joint deformational data, Goodman Jack results and two rock mass classification schemes. Similar deformational moduli were determined from these techniques, except for the Goodman Jack results. The finite element technique was utilized for both the non-linear thermal and mechanical computations. An incremental stiffness method with residual force correction was employed to solve the non-linear problem by piecewise linearization. Two and three dimensional thermomechanical scoping calculations were made to assess the significance of various parameters and associated errors with geometrical idealizations. Both heater tests were modeled as two dimensional axisymmetric geometry with water assumed to be absent. Instrument response was predicted for all of the thermocouples, extensometers, USBM borehole deformation and IRAD gages for the entire duration of both tests

  16. Design of PCCV for Tsuruga No.2 plant of Japan Atomic Power Co

    International Nuclear Information System (INIS)

    Toda, Shiro; Yamada, Yasushi; Kuno, Toshio.

    1987-01-01

    The reactor containment vessel for Tsuruga No.2 plant is a prestressed concrete structure, the design of which was carried out in USA for three years from August, 1977. The research on PCCVs has been carried out for more than ten years in Japan, but this is the first case adopting it for an actual plant, so the design was advanced by the close cooperation between both Japanese and USA sides so as to conform to Japanese laws and tradition, and the check and review of the design results were jointly carried out. In reactor containment vessels, the internal pressure and temperature rise occurring at the time of LOCA become the main design load. The features of PCCVs as prestressed concrete structures are the utilization of prestress for large scale membrane structures, the vessels are subjected to thermal stress since those contain nuclear reactors, and the sufficient safety to the severe aseismatic condition peculiar to nuclear power stations. The prestressed concrete structure achieves the function of pressure vessels, the steel liner achieves the function of leak prevention, and the concrete achieves the function of radiation shield, and these are combined in one body as PCCVs. A PCCV is composed of a prestressed concrete upper shell and a reinforced concrete foundation. The structure, the standards to be applied, the allowable values of load and materials, the stress analysis, the cross section design and the design reinforcement are reported. (Kako, I.)

  17. Evaluation of bone-seeking novel radiotracer 68Ga-NO2AP-Bisphosphonate for the detection of skeletal metastases in carcinoma breast

    International Nuclear Information System (INIS)

    Passah, Averilicia; Tripathi, Madhavi; Ballal, Sanjana; Yadav, Madhav Prasad; Kumar, Rajeev; Chakraborty, Partha Sarathi; Bal, Chandrasekhar; Roesch, Frank; Meckel, Marian

    2017-01-01

    The successful labelling of bisphosphonates (BP) with 68 Ga using macrocyclic chelators such as the based triazacyclononane (NO2AP) is a step forward in the in-house availability of a novel bone-seeking PET radiopharmaceutical with dual advantage of PET/CT imaging and generator production. In this study, we compared the novel generator-based skeletal radiotracer 68 Ga-1,4,7-triazacyclonone-1,4-diacetic acid ( 68 Ga-NO2AP-BP) with sodium fluoride ( 18 F-NaF) for the detection of skeletal metastases in breast cancer patients. In addition, dosimetric analysis of 68 Ga-NO2AP-BP was performed in a subset of patients. This was a prospective study of histopathologically proven cases of breast cancer patients who were referred for bone scintigraphy and underwent positron emission tomography/computed tomography (PET/CT) with 18 F-NaF and 68 Ga-NO2AP-BP within a week in random order. The scans of each patient were compared both qualitatively for image quality and quantitatively for number of lesions and SUVmax of lesions. Dosimetric analysis was performed in five patients. Their PET/CT scans were acquired at multiple time points and urine and blood samples were collected. Dosimetric calculations were performed using OLINDA/EXM 1.1 software. Statistical analysis was done using Stata 13 (StataCorp) software package. An agreement analysis regarding number of lesions detected with the two skeletal radiotracers was carried out. The image quality of 68 Ga-NO2AP-BP PET/CT scans were comparable to that of 18 F-NaF. There was no statistically significant difference in the SUVmax of lesions, normal bone and lesion to background ratio between the two skeletal radiotracers. There was good agreement in the number of lesions detected by both skeletal radiotracers. The mean whole body effective dose for 68 Ga-NO2AP-BP was 0.00583 mSv/MBq and the effective dose equivalent was 0.0086 mSv/MBq. The excellent lesion detection agreement between 68 Ga-NO2AP-BP and 18 F-NaF favours the former as

  18. Effectiveness of low emission zones: large scale analysis of changes in environmental NO2, NO and NOx concentrations in 17 German cities.

    Directory of Open Access Journals (Sweden)

    Peter Morfeld

    Full Text Available Low Emission Zones (LEZs are areas where the most polluting vehicles are restricted from entering. The effectiveness of LEZs to lower ambient exposures is under debate. This study focused on LEZs that restricted cars of Euro 1 standard without appropriate retrofitting systems from entering and estimated LEZ effects on NO2, NO, and NOx ( = NO2+NO.Continuous half-hour and diffuse sampler 4-week average NO2, NO, and NOx concentrations measured inside and outside LEZs in 17 German cities of 6 federal states (2005-2009 were analysed as matched quadruplets (two pairs of simultaneously measured index values inside LEZ and reference values outside LEZ, one pair measured before and one after introducing LEZs with time differences that equal multiples of 364 days by multiple linear and log-linear fixed-effects regression modelling (covariables: e.g., wind velocity, amount of precipitation, height of inversion base, school holidays, truck-free periods. Additionally, the continuous half-hour data was collapsed into 4-week averages and pooled with the diffuse sampler data to perform joint analysis.More than 3,000,000 quadruplets of continuous measurements (half-hour averages were identified at 38 index and 45 reference stations. Pooling with diffuse sampler data from 15 index and 10 reference stations lead to more than 4,000 quadruplets for joint analyses of 4-week averages. Mean LEZ effects on NO2, NO, and NOx concentrations (reductions were estimated to be at most -2 µg/m(3 (or -4%. The 4-week averages of NO2 concentrations at index stations after LEZ introduction were 55 µg/m(3 (median and mean values or 82 µg/m(3 (95th percentile.This is the first study investigating comprehensively the effectiveness of LEZs to reduce NO2, NO, and NOx concentrations controlling for most relevant potential confounders. Our analyses indicate that there is a statistically significant, but rather small reduction of NO2, NO, and NOx concentrations associated with LEZs.

  19. Evaluation of bone-seeking novel radiotracer {sup 68}Ga-NO2AP-Bisphosphonate for the detection of skeletal metastases in carcinoma breast

    Energy Technology Data Exchange (ETDEWEB)

    Passah, Averilicia; Tripathi, Madhavi; Ballal, Sanjana; Yadav, Madhav Prasad; Kumar, Rajeev; Chakraborty, Partha Sarathi; Bal, Chandrasekhar [All India Institute of Medical Sciences, Department of Nuclear Medicine, Ansari Nagar, New Delhi (India); Roesch, Frank; Meckel, Marian [Johannes-Gutenberg-University, Nuclear Chemistry, Mainz (Germany)

    2017-01-15

    The successful labelling of bisphosphonates (BP) with {sup 68}Ga using macrocyclic chelators such as the based triazacyclononane (NO2AP) is a step forward in the in-house availability of a novel bone-seeking PET radiopharmaceutical with dual advantage of PET/CT imaging and generator production. In this study, we compared the novel generator-based skeletal radiotracer {sup 68}Ga-1,4,7-triazacyclonone-1,4-diacetic acid ({sup 68}Ga-NO2AP-BP) with sodium fluoride ({sup 18}F-NaF) for the detection of skeletal metastases in breast cancer patients. In addition, dosimetric analysis of {sup 68}Ga-NO2AP-BP was performed in a subset of patients. This was a prospective study of histopathologically proven cases of breast cancer patients who were referred for bone scintigraphy and underwent positron emission tomography/computed tomography (PET/CT) with {sup 18}F-NaF and {sup 68}Ga-NO2AP-BP within a week in random order. The scans of each patient were compared both qualitatively for image quality and quantitatively for number of lesions and SUVmax of lesions. Dosimetric analysis was performed in five patients. Their PET/CT scans were acquired at multiple time points and urine and blood samples were collected. Dosimetric calculations were performed using OLINDA/EXM 1.1 software. Statistical analysis was done using Stata 13 (StataCorp) software package. An agreement analysis regarding number of lesions detected with the two skeletal radiotracers was carried out. The image quality of {sup 68}Ga-NO2AP-BP PET/CT scans were comparable to that of {sup 18}F-NaF. There was no statistically significant difference in the SUVmax of lesions, normal bone and lesion to background ratio between the two skeletal radiotracers. There was good agreement in the number of lesions detected by both skeletal radiotracers. The mean whole body effective dose for {sup 68}Ga-NO2AP-BP was 0.00583 mSv/MBq and the effective dose equivalent was 0.0086 mSv/MBq. The excellent lesion detection agreement between

  20. Evaluation of the United States National Air Quality Forecast Capability experimental real-time predictions in 2010 using Air Quality System ozone and NO2 measurements

    Directory of Open Access Journals (Sweden)

    T. Chai

    2013-10-01

    Full Text Available The National Air Quality Forecast Capability (NAQFC project provides the US with operational and experimental real-time ozone predictions using two different versions of the three-dimensional Community Multi-scale Air Quality (CMAQ modeling system. Routine evaluation using near-real-time AIRNow ozone measurements through 2011 showed better performance of the operational ozone predictions. In this work, quality-controlled and -assured Air Quality System (AQS ozone and nitrogen dioxide (NO2 observations are used to evaluate the experimental predictions in 2010. It is found that both ozone and NO2 are overestimated over the contiguous US (CONUS, with annual biases of +5.6 and +5.1 ppbv, respectively. The annual root mean square errors (RMSEs are 15.4 ppbv for ozone and 13.4 ppbv for NO2. For both species the overpredictions are most pronounced in the summer. The locations of the AQS monitoring sites are also utilized to stratify comparisons by the degree of urbanization. Comparisons for six predefined US regions show the highest annual biases for ozone predictions in Southeast (+10.5 ppbv and for NO2 in the Lower Middle (+8.1 ppbv and Pacific Coast (+7.1 ppbv regions. The spatial distributions of the NO2 biases in August show distinctively high values in the Los Angeles, Houston, and New Orleans areas. In addition to the standard statistics metrics, daily maximum eight-hour ozone categorical statistics are calculated using the current US ambient air quality standard (75 ppbv and another lower threshold (70 ppbv. Using the 75 ppbv standard, the hit rate and proportion of correct over CONUS for the entire year are 0.64 and 0.96, respectively. Summertime biases show distinctive weekly patterns for ozone and NO2. Diurnal comparisons show that ozone overestimation is most severe in the morning, from 07:00 to 10:00 local time. For NO2, the morning predictions agree with the AQS observations reasonably well, but nighttime concentrations are overpredicted

  1. Enhanced UHF RFID tags for drug tracing.

    Science.gov (United States)

    Catarinucci, Luca; Colella, Riccardo; De Blasi, Mario; Patrono, Luigi; Tarricone, Luciano

    2012-12-01

    Radio Frequency Identification (RFID) technology is playing a crucial role for item-level tracing systems in healthcare scenarios. The pharmaceutical supply chain is a fascinating application context, where RFID can guarantee transparency in the drug flow, supporting both suppliers and consumers against the growing counterfeiting problem. In such a context, the choice of the most adequate RFID tag, in terms of shape, frequency, size and reading range, is crucial. The potential presence of items containing materials hostile to the electromagnetic propagation exasperates the problem. In addition, the peculiarities of the different RFID-based checkpoints make even more stringent the requirements for the tag. In this work, the performance of several commercial UHF RFID tags in each step of the pharmaceutical supply chain has been evaluated, confirming the expected criticality. On such basis, a guideline for the electromagnetic design of new high-performance tags capable to overcome such criticalities has been defined. Finally, driven by such guidelines, a new enhanced tag has been designed, realized and tested. Due to patent pending issues, the antenna shape is not shown. Nevertheless, the optimal obtained results do not lose their validity. Indeed, on the one hand they demonstrate that high performance item level tracing systems can actually be implemented also in critical operating conditions. On the other hand, they encourage the tag designer to follow the identified guidelines so to realize enhanced UHF tags.

  2. Impact of passenger car NOX emissions on urban NO2 pollution - Scenario analysis for 8 European cities

    Science.gov (United States)

    Degraeuwe, Bart; Thunis, Philippe; Clappier, Alain; Weiss, Martin; Lefebvre, Wouter; Janssen, Stijn; Vranckx, Stijn

    2017-12-01

    Residents of large European cities are exposed to NO2 concentrations that often exceed the established air quality standards. Diesel cars have been identified as a major contributor to this situation; yet, it remains unclear to which levels the NOX emissions of diesel cars have to decrease to effectively mitigate urban NO2 pollution across Europe. Here, we take a continental perspective and model urban NO2 pollution in a generic street canyon of 8 major European cities for various NOX emission scenarios. We find that a reduction in the on-road NOX emissions of diesel cars to the Euro 6 level can in general decrease the regional and urban NO2 concentrations and thereby the frequency of exceedances of the NO2 air quality standard. High NO2 fractions in the NOX emissions of diesel cars tend to increase the urban NO2 concentrations only in proximity of intense road traffic typically found on artery roads in large cities like Paris and London. In cities with a low share of diesel cars in the vehicle fleet such as Athens or a high contribution from the NO2 background to the urban NO2 pollution such as Krakow, measures addressing heavy-duty vehicles, and the manufacturing, energy, and mining industry are necessary to decrease urban air pollution. We regard our model results as robust albeit subject to uncertainty resulting from the application of a generic street layout. With small modifications in the input parameters, our model could be used to assess the impact of NOX emissions from road transport on NO2 air pollution in any European city.

  3. RAY TRACING RENDER MENGGUNAKAN FRAGMENT ANTI ALIASING

    Directory of Open Access Journals (Sweden)

    Febriliyan Samopa

    2008-07-01

    although there is some situation where the time effectiveness is equal. This is possible since the process of intersection searching on FAA needs additional time. Rendered images using FAA are relatively similar to those using OGSS.   Kata Kunci: Ray Tracing, Fragment Anti Aliasing, Ordered Grid Super Sampling, Render, Sampling, Jaggies

  4. Subsurface Interim Measures/Interim Remedial Action Plan/Environmental Assessment and Decision Document, Operable Unit No. 2

    International Nuclear Information System (INIS)

    1992-01-01

    The subject Interim Measures/Interim Remedial Action plan/Environmental Assessment (IM/IRAP/EA) addresses residual free-phase volatile organic compound (VOC) contamination suspected in the subsurface within an area identified as Operable Unit No. 2 (OU2). This IM/IRAP/EA also addresses radionuclide contamination beneath the 903 Pad at OU2. Although subsurface VOC and radionuclide contamination on represent a source of OU2 ground-water contamination, they pose no immediate threat to public health or the environment. This IM/IRAP/EA identifies and evaluates interim remedial actions for removal of residual free-phase VOC contamination from three different subsurface environments at OU2. The term ''residual'' refers to the non-aqueous phase contamination remaining in the soil matrix (by capillary force) subsequent to the passage of non-aqueous or free-phase liquid through the subsurface. In addition to the proposed actions, this IM/IRAP/EA presents an assessment of the No Action Alternative. This document also considers an interim remedial action for the removal of radionuclides from beneath the 903 Pad

  5. Distributed trace using central performance counter memory

    Science.gov (United States)

    Satterfield, David L.; Sexton, James C.

    2013-01-22

    A plurality of processing cores, are central storage unit having at least memory connected in a daisy chain manner, forming a daisy chain ring layout on an integrated chip. At least one of the plurality of processing cores places trace data on the daisy chain connection for transmitting the trace data to the central storage unit, and the central storage unit detects the trace data and stores the trace data in the memory co-located in with the central storage unit.

  6. Probabilistic Connections for Bidirectional Path Tracing

    OpenAIRE

    Popov, Stefan; Ramamoorthi, Ravi; Durand, Fredo; Drettakis, George

    2015-01-01

    International audience; Bidirectional Path Tracing Probabilistic Connections for Bidirectional Path Tracing Figure 1: Our Probabilistic Connections for Bidirectional Path Tracing approach importance samples connections to an eye sub-path, and greatly reduces variance, by considering and reusing multiple light sub-paths at once. Our approach (right) achieves much higher quality than bidirectional path-tracing on the left for the same computation time (~8.4 min).. Abstract Bidirectional path tr...

  7. Bayesian Contact Tracing for Communicable Respiratory Disease

    Science.gov (United States)

    Shalaby, Ayman; Lizotte, Daniel

    2013-01-01

    Objective The purpose of our work is to develop a system for automatic contact tracing with the goal of identifying individuals who are most likely infected, even if we do not have direct diagnostic information on their health status. Control of the spread of respiratory pathogens (e.g. novel influenza viruses) in the population using vaccination is a challenging problem that requires quick identification of the infectious agent followed by large-scale production and administration of a vaccine. This takes a significant amount of time. A complementary approach to control transmission is contact tracing and quarantining, which are currently applied to sexually transmitted diseases (STDs). For STDs, identifying the contacts that might have led to disease transmission is relatively easy; however, for respiratory pathogens, the contacts that can lead to transmission include a huge number of face-to-face daily social interactions that are impossible to trace manually. Introduction The evolution of novel influenza viruses in humans is a biological phenomenon that can not be stopped. All existing data suggest that vaccination against the morbidity and mortality of the novel influenza viruses is our best line of defence. Unfortunately, vaccination requires that the infectious agent to be quickly identified and a safe vaccine in large quantities is produced and administered. As was witnessed with the 2009 H1N1 influenza pandemic, these steps took a frustratingly long period during which the novel influenza virus continued its unstoppable and rapid global spreading. In addition to the different vaccination strategies (e.g. random mass vaccination, age structured vaccination), isolation and quarantining of infected individuals is another effective method used by the public health agencies to control the spreading of infectious diseases. Isolation is effective against any infectious disease, however it can be very hard to detect infectious individuals in the population when

  8. CNG acid gas removal process. Technical progress report No. 2, 1 February-30 April 1981

    Energy Technology Data Exchange (ETDEWEB)

    Adler, R.J.; Auyang, L.; Brown, W.R.; Cook, W.J.; Gardner, N.C.; Keyvani, M.; Liu, Y.C.

    1981-01-01

    During the second quarter of the CNG Acid Gas Removal Project, 4 subtasks were active. Within Subtask 1.1, melter design studies were performed to identify methods of improving melting rates in the CNG crystallizer. Greatly enhanced melting rates are thought possible with a melter configuration that excludes liquid carbon dioxide from the melting region and allows more intimate contact of the vapor and solid carbon dioxide. Also within Subtask 1.1, a review of triple-point desalination process literature was completed. Within Subtask 2.2, reconstruction and testing of the vapor-liquid solid equilibrium apparatus is nearly complete. Test operation with the carbon dioxide - ethylene binary system produced data in excellent agreement with published data for this system. The increased sample volume permitted minimum disturbance of the equilibrium states, and vapor-recirculation agitation permitted rapid attainment of equilibrium. Within Subtask 2.3, the original CNG crystallizer is being reactivated to measure separation factors for carbonyl sulfide and trace contaminants. Primary efforts to date have focused on reactivation of the crystallizer. However, a successful run with pure carbon dioxide was achieved late in April. Within Subtask 3.1, conceptual studies to assess treatment of low carbon dioxide crude gases focused on three processes: (1) a precompression process to boost the partial pressure of carbon dioxide; (2) a modified non-selective physical absorption process; and (3) a modified non-selective physical absorption process with solvent slurry. None of these three processes are as attractive as the modified physical absorption process incorporating the CNG crystallizer reported in the fist quarterly report. 12 references, 6 figures, 1 table.

  9. Tracing Utopia in 'Utopia Station'

    DEFF Research Database (Denmark)

    Schwarzbart, Judith

    Art (Publication due in 2012)). But it seems to differ noticeable from the ideologically driven concept(s) of the 20th century avant-garde. The paper will suggest that we in experiments with openness and structure, with an ambivalent engagement in popular culture and everyday life, and complex double...... at the many layers of discourse, ‘thinking-in-process’ and collaboration. These processes led to particular presentational formats (display) and architectural frameworks for activities, and gave way to a variety of other material and situated performative modes of audience encounters. Here, we can trace avant......-garde ideas about radical democracy through open processes and active involvement of audience-participants, we can trace formal (architectural) structures back to the Russian constructivism and many other links back in time, but the central question remains if theses ethical-political and aesthetic gestures...

  10. Trace elements and bone health.

    Science.gov (United States)

    Zofková, Ivana; Nemcikova, Petra; Matucha, Petr

    2013-08-01

    The importance of nutrition factors such as calcium, vitamin D and vitamin K for the integrity of the skeleton is well known. Moreover, bone health is positively influenced by certain elements (e.g., zinc, copper, fluorine, manganese, magnesium, iron and boron). Deficiency of these elements slows down the increase of bone mass in childhood and/or in adolescence and accelerates bone loss after menopause or in old age. Deterioration of bone quality increases the risk of fractures. Monitoring of homeostasis of the trace elements together with the measurement of bone density and biochemical markers of bone metabolism should be used to identify and treat patients at risk of non-traumatic fractures. Factors determining the effectivity of supplementation include dose, duration of treatment, serum concentrations, as well as interactions among individual elements. Here, we review the effect of the most important trace elements on the skeleton and evaluate their clinical importance.

  11. The Bulletin of Military Operations Research, PHALANX, Vol. 31, No. 2.

    Science.gov (United States)

    1998-06-01

    An addition- al benefit gained while stationed here in the Washington, DC area was the stability that was achieved for my family: my son will...Bexfield, FS, drafted an addition to our MORS organization manu- al that will provide guidance to us in the future for evaluating joint meetings. Also...and unwise complexity, which is Occam’s Razor (William of Occam—alternatively spelled Ockham , Quodlibeta Septem, circa 1320 AD), "essentia non sunt

  12. Requirement Tracing using Term Extraction

    OpenAIRE

    Al-Saati, Najla; Abdul-Jaleel, Raghda

    2015-01-01

    Requirements traceability is an essential step in ensuring the quality of software during the early stages of its development life cycle. Requirements tracing usually consists of document parsing, candidate link generation and evaluation and traceability analysis. This paper demonstrates the applicability of Statistical Term Extraction metrics to generate candidate links. It is applied and validated using two data sets and four types of filters two for each data set, 0.2 and 0.25 for MODIS, 0...

  13. Trace Amines and Cocaine Abuse

    OpenAIRE

    Li, Jun-Xu

    2014-01-01

    Cocaine addiction remains a clinical challenge with no effective pharmacotherapy available. Trace amine associated receptor (TAAR) 1 represents a promising drug target for the modulation of dopaminergic system and stimulant abuse. This Viewpoint discusses the emerging data which strongly suggest that TAAR 1 functions as a molecular “brake” that controls the addiction-related effects of cocaine and could be a novel drug target for the development of efficacious pharmacothe...

  14. Trace Replay and Network Simulation Tool

    Energy Technology Data Exchange (ETDEWEB)

    2017-09-22

    TraceR Is a trace replay tool built upon the ROSS-based CODES simulation framework. TraceR can be used for predicting network performance and understanding network behavior by simulating messaging In High Performance Computing applications on interconnection networks.

  15. Precambrian biota: protistan origin of trace fossils?

    Science.gov (United States)

    Pawlowski, Jan; Gooday, Andrew J

    2009-01-13

    Some Precambrian trace fossils have been presented as evidence for the early origin of bilaterians; the recent finding that large amoeboid protists leave macroscopic traces at the bottom of the deep ocean questions the metazoan nature of early trace fossils, stressing the importance of single-cell organisms in Precambrian biota.

  16. Installation modification of the reactor No.2 of Ikata nuclear power plant of Shikoku Electric Power Company, Inc

    International Nuclear Information System (INIS)

    1980-01-01

    The application was made on August 25, 1979, from the president of the Shikoku Electric Power Company, Inc., to the Minister of International Trade and Industry, relating to the installation modification of the reactor No. 2 in the Ikata nuclear power plant. The inquiry was submitted on September 28, 1979, from the Minister of International Trade and Industry to the Nuclear Safety Commission, after the safety evaluation in the Ministry of International Trade and Industry, and the investigation and deliberation were started on October 1, 1979, in the Nuclear Safety Commission. The content of the modification is to add the circuit actuated by the abnormal low pressure signal of the reactor to the actuating circuit of the emergency core cooling system (ECCS) and to increase the new fuel storage capacity from about 1/3 core to about 2/3 core. The additional signal circuit is composed of the logic circuit of ''2 out of 4'' and is multichannel design. The circuit is independent from the reactor control system and the conventional signal circuit of the concurrence of low pressure in the reactor and low level in the pressurizer. With the addition of the circuit of abnormal low pressure signal of the reactor, the countermeasures for preventing ECCS start by mistake are also added. These modifications give no influence to the functions of the reactor control system and reactor protection system. The function and the performance of ECCS were analyzed and evaluated accompanying these modifications assuming the loss of coolant accident. Concerning the new fuel storage capacity, the type of racks is modified from angle type to can type, and the subcriticality is kept even at the time of water flood. (Nakai, Y.)

  17. Traces et espaces de consommation

    Directory of Open Access Journals (Sweden)

    Franck Cochoy

    2016-10-01

    Full Text Available L’avènement des technologies numériques mobiles contribue à une évolution des modalités de distribution et de consommation. Le présent article porte sur l’usage des QR-codes, ces codes-barres bidimensionnels qui offrent à tout usager équipé d’un smartphone l’accès à des contenus commerciaux en ligne. Ils participent à l’Internet des objets et donc au couplage entre espace physique et univers numérique. Ils permettent aussi la collecte de traces numériques porteuses de sens pour les professionnels mais aussi pour les sciences sociales. Grâce à ces traces, on peut comprendre les nouveaux liens marchands tissés entre l’espace physique et le développement de flux informationnels continus. À partir de l’analyse des traces enregistrées à l’occasion de la visite des QR-codes apposés sur trois produits alimentaires (une boîte de sel, une barre chocolatée, une bouteille d’eau, notre enquête s’attache à expliciter les enjeux théoriques, méthodologiques et analytiques du processus de numérisation de l’espace de mobilité physique marchand.

  18. Boreal forest fire emissions in fresh Canadian smoke plumes: C1-C10 volatile organic compounds (VOCs, CO2, CO, NO2, NO, HCN and CH3CN

    Directory of Open Access Journals (Sweden)

    M. Yang

    2011-07-01

    Full Text Available Boreal regions comprise about 17 % of the global land area, and they both affect and are influenced by climate change. To better understand boreal forest fire emissions and plume evolution, 947 whole air samples were collected aboard the NASA DC-8 research aircraft in summer 2008 as part of the ARCTAS-B field mission, and analyzed for 79 non-methane volatile organic compounds (NMVOCs using gas chromatography. Together with simultaneous measurements of CO2, CO, CH4, CH2O, NO2, NO, HCN and CH3CN, these measurements represent the most comprehensive assessment of trace gas emissions from boreal forest fires to date. Based on 105 air samples collected in fresh Canadian smoke plumes, 57 of the 80 measured NMVOCs (including CH2O were emitted from the fires, including 45 species that were quantified from boreal forest fires for the first time. After CO2, CO and CH4, the largest emission factors (EFs for individual species were formaldehyde (2.1 ± 0.2 g kg−1, followed by methanol, NO2, HCN, ethene, α-pinene, β-pinene, ethane, benzene, propene, acetone and CH3CN. Globally, we estimate that boreal forest fires release 2.4 ± 0.6 Tg C yr−1 in the form of NMVOCs, with approximately 41 % of the carbon released as C1-C2 NMVOCs and 21 % as pinenes. These are the first reported field measurements of monoterpene emissions from boreal forest fires, and we speculate that the pinenes, which are relatively heavy molecules, were detected in the fire plumes as the result of distillation of stored terpenes as the vegetation is heated. Their inclusion in smoke chemistry models is expected to improve model predictions of secondary organic aerosol (SOA formation. The fire-averaged EF of dichloromethane or CH2Cl2, (6.9 ± 8.6 × 10−4 g kg−1, was not significantly different from zero and supports recent findings that its global biomass burning source appears to have been overestimated. Similarly, we found no evidence for emissions of chloroform (CHCl3 or methyl

  19. Instrument inter-comparison of glyoxal, methyl glyoxal and NO2 under simulated atmospheric conditions

    Science.gov (United States)

    Thalman, R.; Baeza-Romero, M. T.; Ball, S. M.; Borrás, E.; Daniels, M. J. S.; Goodall, I. C. A.; Henry, S. B.; Karl, T.; Keutsch, F. N.; Kim, S.; Mak, J.; Monks, P. S.; Muñoz, A.; Orlando, J.; Peppe, S.; Rickard, A. R.; Ródenas, M.; Sánchez, P.; Seco, R.; Su, L.; Tyndall, G.; Vázquez, M.; Vera, T.; Waxman, E.; Volkamer, R.

    2014-08-01

    glyoxal (0.58 < R2 < 0.68) than for glyoxal (0.79 < R2 < 0.99). The intercepts of correlations were insignificant for the most part; slopes varied by less than 5% for instruments that also measure NO2. For glyoxal and methyl glyoxal the slopes varied by less than 12% and 17% (both 3-sigma) between inherently calibrated instruments (i.e., calibration from knowledge of the absorption cross-section). We find a larger variability among in situ techniques that employ external calibration sources (75% to 90%, 3-sigma), and/or techniques that employ offline analysis. Our inter-comparison reveal existing differences in reports about precision and detection limits in the literature, and enables comparison on a common basis by observing a common airmass. Finally, we evaluate the influence of interfering species (e.g., NO2, O3 and H2O) of relevance in field and laboratory applications. Techniques now exist to conduct fast and accurate measurements of glyoxal at ambient concentrations, and methyl glyoxal under simulated conditions. However, techniques to measure methyl glyoxal at ambient concentrations remain a challenge, and would be desirable.

  20. Instrument intercomparison of glyoxal, methyl glyoxal and NO2 under simulated atmospheric conditions

    Science.gov (United States)

    Thalman, R.; Baeza-Romero, M. T.; Ball, S. M.; Borrás, E.; Daniels, M. J. S.; Goodall, I. C. A.; Henry, S. B.; Karl, T.; Keutsch, F. N.; Kim, S.; Mak, J.; Monks, P. S.; Muñoz, A.; Orlando, J.; Peppe, S.; Rickard, A. R.; Ródenas, M.; Sánchez, P.; Seco, R.; Su, L.; Tyndall, G.; Vázquez, M.; Vera, T.; Waxman, E.; Volkamer, R.

    2015-04-01

    > 45%) for methyl glyoxal (0.58 < R2 < 0.68) than for glyoxal (0.79 < R2 < 0.99). The intercepts of correlations were insignificant for the most part (below the instruments' experimentally determined detection limits); slopes further varied by less than 5% for instruments that could also simultaneously measure NO2. For glyoxal and methyl glyoxal the slopes varied by less than 12 and 17% (both 3-σ) between direct absorption techniques (i.e., calibration from knowledge of the absorption cross section). We find a larger variability among in situ techniques that employ external calibration sources (75-90%, 3-σ), and/or techniques that employ offline analysis. Our intercomparison reveals existing differences in reports about precision and detection limits in the literature, and enables comparison on a common basis by observing a common air mass. Finally, we evaluate the influence of interfering species (e.g., NO2, O3 and H2O) of relevance in field and laboratory applications. Techniques now exist to conduct fast and accurate measurements of glyoxal at ambient concentrations, and methyl glyoxal under simulated conditions. However, techniques to measure methyl glyoxal at ambient concentrations remain a challenge, and would be desirable.